​Conceived by GM styling boss Bill Mitchell, the Silver Arrow III was a dramatic reinterpretation of the production boattail Riviera introduced in 1971.

Introduced at the 1972 Detroit Auto Show at Cobo Hall, the Silver Arrow III boasted a number of advanced features, including four-wheel disc brakes and Max Trac, an early form of electronic traction control that was offered on the production Riviera as well. Above the backlight at the trailing edge of the roof was a set of high-level warning lamps that also served as secondary directional indicators. Additional show-car touches included a fully chromed and detailed 455 CID Buick V8 under the hood.
When the Silver Arrow III appeared on show floor at Detroit, Chicago, and elsewhere in 1972, we’re not quite sure what the ultimate effect was, except perhaps to throw some shade on the more conservatively styled production Riviera. It is known that Mitchell was quite proud of the two Silver Arrows—here, below, he’s shown posing with the pair. Both Silver Arrow I and Silver Arrow III are still in existence today.   -Photos courtesy of General Motors. ​

Another intriguing automotive mystery: Whatever became of the one-of-one 1965 Mustang concept created by Carrozzeria Bertone of Italy? Could it still exist?
First shown at the New York International Auto Show in the spring of 1965, the stunning Mustang Bertone was commissioned from the renowned Turinese coachbuilding firm by a magazine publisher:  L. Scott Bailey, founder of Automobile Quarterly, the ritzy hardbound car periodical. (It ceased publication in 2012.) The designer was none other than Giorgetto Giugiaro, then just 27, a few years before he ventured out on his own to launch his own famous studio, Ital Design. In New York, the Italian Mustang took best of show honors, and it was a sensation at the London, Paris, and Turin motor shows as well. Then the car disappeared from view and it hasn’t been seen in public since.

​The Bertone Mustang bears far more resemblance to familiar Giugiaro designs like the Iso Grifo and the Fiat Dino than to any Ford Motor Company product. Even the Ford wheels were exchanged for Bertone-designed Campagnolo magnesium castings. The quad headlights were hidden behind electrically operated grille doors, and as the story goes, the radiator and front bulkhead were sectioned to accommodate the Bertone’s slimmer profile, a good two inches lower than a production Mustang. According to Bailey, Italian stylists didn’t think much of the production Mustang’s styling, finding it too ordinary and sedan-like.
Wearing distinctive silver-turquoise metallic paint, the Bertone Mustang made its next appearance on the cover of Road & Track magazine in January of 1966, below. There would be one more appearance in print, also in Road & Track: a Bertone ad in the September 1967 issue listed the Mustang for sale with an asking price of $10,000, “one-third its actual cost.” From there, the Mustang has never been seen or heard from again, apparently. Before he passed away in 2012, Bailey attempted to track down the unique Mustang, but nothing ever turned up.

Chrysler styling chief Virgil Exner rocked the Motor City to its core with the Chrysler Forward Look line for 1957. But behind the scenes, he had even bigger ideas. 
The career of an auto designer follows a familiar arc, many will say. As the years go by, their work tends to become more refined and restrained. Not Virgil Exner, vice president of design at the Chrysler Corporation through the ’50s and the architect of the company’s Forward Look. As his career advanced, his designs only became more daring and audacious. His 1957 Chrysler family of cars rocked the Detroit auto industry to its core with their low, sleek lines and bold tail fins, throwing GM and Ford back on their heels. And while it never saw production, back within the walls of the Chrysler styling studios, Exner had an even bolder stroke held in reserve: the Chrysler 300C Ghia, also known as Project 613.

​The color rendering above and full-size clay model below show the essential elements of Project 613: It’s the car that became the production 1957 Chrysler 300C, more or less, but with some obvious revisions.  First, there’s a radically faired-in application of one of Exner’s favorite gimmicks, the faux continental spare tire. (The tack-on tire cover on production Chrysler products was labeled by critics the “washing machine lid” or “toilet seat.”) Next, Project 613 sports the biggest, tallest, most spectacular tail fins ever seen on a Chrysler product, partially blocking the rear side glass. Virgil Exner, unleashed.

​Hardcore Mopar enthusiasts will notice that the Project 613 hardtop version uses the Plymouth/Dodge greenhouse with its slimmer C pillars instead of the bulkier roof structure found on Chysler production models that year. A fully functional, running and driving prototype, Project 613 reportedly rode on a 122-inch wheelbase, four inches shorter than the production ’57 Chrysler.

The body for the one-off  was constructed by Carrozzeria Ghia of Turin, Chrysler’s go-to Italian coachbuilder for show cars and other special projects. Upon its completion in mid-early 1956, Project 613 became Exner’s daily transportation—photos show it parked in the driveway of his home in the Detroit suburbs, and it was said to be one of his favorite cars. According to Exner’s son, Virgil Exner Jr, the car was then known as the “Chrysler 500.”
The eventual fate of Exner’s  fabulously finned Mopar is unknown (to us, anyway) but fortunately, the story doesn’t end here. Chrysler enthusiast Édouard Rodrigue of Québec constructed a faithful replica of the Ghia prototype using a ’57 Plymouth platform and ’57 Chrysler sheet metal components. The recreation took six years, is powered by a 392 CID Chrysler hemi V8 in 300C tune, and, according to Mr. Rodrigue, is “95 percent identical to the original prototype.” 
​Photo below courtesy of Lemire Media. 

The concept of a mid-engine Corvette is almost as old as the Corvette itself. Here’s the General’s first attempt at the driver-first vehicle layout, the 1968 Chevrolet Astro II.
If the press reports to date are any indication, it looks like the 2020 C8 mid-engine Corvette is going to be a winner. Almost universally, the automotive media has applauded its handling, ride, performance, and packaging. In their eyes, the new C8 is everything a Corvette ought to be. Maybe we shouldn’t be surprised by all the thumbs up from the reviewers. After all, General Motors has been kicking around the mid-engined package for future Corvettes for many decades now, so they’ve had plenty of time to get it right. The automaker’s first working prototype was the Chevrolet Astro II way back in 1968, bearing the internal GM designation XP-880.

​Above, the guy in the blazer is checking out the Astro II’s novel (for 1968, anyway) drivetrain setup: a 427 cubic-inch big-block V8 coupled to a two-speed automatic transaxle borrowed from the 1961-63 Pontiac Tempest—which in turn was based on the Corvair Powerglide, a unit not known for its torque capacity. The body shell is fiberglass, naturally, and everything rides on a Lotus-like backbone chassis of welded steel. Hidden in plain sight along the right side of the engine is a BF Goodrich Space Saver collapsing spare tire. The fuel tank resides on the other side, while the radiator is mounted over and behind the axle, aided by a large grille in the tilt-up bonnet.
First shown to the public at the 1968 New York Auto Show, the Astro II was a mere 43.7 inches tall. We note that for its debut, the show car was not officially badged as a Corvette, a sort-of tradition in Corvette concept vehicles. While the Astro II is widely heralded as the first mid-engine Corvette, it wasn’t the first mid-engine Chevy R&D vehicle; precursors included the CERV I and CERV II test mules and the GSII racer. And yes, there was an Astro I. That name was applied to a futuristic Corvair-based dream car that seems otherwise unrelated to the Astro II.

​Above, this overhead view of the Astro II’s cockpit illustrates one shortcoming of the backbone frame layout: In this case, there’s scarcely enough lateral space remaining for a driver and passenger. Like the make-do transaxle, the cramped cockpit demonstrates that the mid-engine Corvette was a work in progress. But then, that’s the purpose of concepts and prototypes: to explore all the advantages and pitfalls of various ideas. The new C8 Corvette has been acclaimed as one of the most comfortable mid-engine sports cars ever, so it appears they got that part right.
The rear-quarter view below recalls the Porsche 904 a bit, and shows that Chevrolet experimented with several wheel-and-tire packages over the years. Here, the cast-spoke aluminum wheels usually seen have been exchanged for production-style Chevrolet Rally wheels, caps, and trim rings. In various forms, the Astro II appeared on the cover of Road & Track magazine in July of 1968, Motor Trend in December 1969, and no doubt countless others. And so, with the 2020 C8 Corvette, another tradition comes to an end: magazines perpetually teasing their readers with headlines like “Coming soon—a mid-engine Corvette?” By the way, XP-880 is still around in pristine condition, and is usually on display at the GM Heritage Center in Sterling Heights, Michigan.

More than once, Chevrolet designers have toyed with the idea of a four/five-place Corvette. One of them even joined the GM Motorama show car fleet for a time—the 1956 Corvette Impala. 

Work began on the five-place Corvette project, known internally at GM as XP-101, in July of 1955, and the Impala made its first public appearance in the General Motors Motorama at the Waldorf Astoria Hotel in New York on January 19, 1956. GM stylists Carl Renner and Bob Cadaret included key elements of the two-seater production Corvette in the Impala’s look, including the large, Italianate radiator opening in the front, filled with a chrome grille bar with 13 sparkling teeth. (Production 1953-1957 Corvettes used the same number of teeth, coincidentally.) Discrete badging on the front header panel and rear deck indicated that despite the rear seat, the Impala was indeed a Corvette.

​The body—fiberglass, naturally, with a brushed stainless roof panel—rode on a conventional Chevy sedan chassis with 116.5-inch wheelbase, with short-long arm independent front suspension and a live axle with leaf springs at the rear. A Corvette 265 CID V8 equipped with two-four-barrel carbs, rated at 225 hp, was coupled to a Powerglide two-speed automatic gearbox, with the exhaust pipes snaked through the driveshaft tunnel. It was all fairly standard underneath, although real wire wheels with knock-off hubs supplied some sports car flavor. One area where the Corvette Impala broke new ground was in its innovative styling and interior.

​A folding armrest allowed occasional three-abreast seating in the front, with room for two more passengers in the coupe’s rear seat. The dramatic Interior fabrics included blue vinyl seat covers with a contrasting silver cloth in a heavy crossweave pattern. Instruments and controls were concentrated in a module directly in front of the driver, with an unusual speedometer that featured a horizontal array of sequential lamps that lit up in progressively brighter red as vehicle speed increased.

​Originally finished in metallic turquoise, the Impala was repainted in medium metallic blue for the 1957 Motorama show season, and it made its debut in the new color at the Chicago Auto Show that year. While the Impala was said to be fully roadworthy, unlike many GM show cars, it was reportedly scrapped at some point after the ’57 show season, unfortunately.

As we know, there would never be a production Corvette with a rear seat, though there were a few more experiments. However, two of the show car’s features did find their way into Chevrolet showrooms in 1958: the novel reverse-angle C pillar and the Impala nameplate, which is used on Chevrolet passenger cars to the current day.