Posted by marcmx:
<<Don't forget the only boxer I can think of out of  Detroit, the Corvair. Six cylinders, air cooled and ranging from 95hp to 180hp.>>
Scheisse, I totally forgot about the 'Vair Monza Spyder! Good catch, marcmax! This confession is especially troubling for me, for reasons below:
During summers in college, I worked for my uncle, who owned a Chevrolet-Cadillac franchise in Central Virginia. My job, particularly in the Service Department, permitted me to drive some of the better mass-produced cars of the period: several 63-66 Corvettes (pre-Stingray, developed by Zora Arkos-Duntov, a design/racing legend of mid-20th century), and 120 miles in a Jag XK-150. But my favorite? A 1964, 180 hp.
supercharged (not a turbo) Corvair Monza Spyder convertible. Though it didn't have quite the top end of the 'Vette or the Jag (or the Studebaker Golden Hawk or Avanti, for that matter), the '64 Spyder was the quickest, most agile USA-manufactured car I've ever driven! (Chevrolet dumbed down the Spyder in '65, so there was only one great year. (]

( ) It cornered like a demon, and was astonishingly exciting to drive in twisties, even on the horrible tires of the period.
Brief explaniation! The Corvair was horribly maligned by the Ralph Nader "Unsafe At Any Speed" scandal. Nader arguably had a case for the first (1960-62) models, for the 'Vair during those years could, if cornered hard, break loose its rear end and spin. (Not a good thing for a rear-engine car.) But then, the 'Vair had been conceived as a car for Granny to drive economically to the supermarket, so there was a question of the design envelope being torn by radical use. By the time Nader's book was published, Chevrolet already had redesigned the 'Vair's rear suspension & eliminated the problem. But no matter: The book was a sensation, then GM compromised its defense by allegedly invaded Nader's privacy rights. GM further compounded the problem by not vigorously defending the Corvair in the legal proceedings. To make matters even worse, the dealers' service department mechanics hated working on Corvairs, and (I suspect) therefore didn't do a great job on them. (I suspect this was because they hadn't been trained adequately on what was at the time a radically different engine from those that American technicians were accustomed to seeing.) Result: Corvairs had problems from (1) oil leaks (valve cover seals) and (2) inner cylinders overheating because of inadequate air flow. (Contemporary VW airhead mechanics had a similar problem with No. 3 cylinder tending to overheat; they solved this problem by setting looser tolerances when adjusting the valves of No. 3. But no one at GM would deign to acquire information by learning from a foreign competitor.)
Result: the Corvair died prematurely from the combination of horrible PR, lack of
huevos among GM executives, and lack of commitment at dealer level.
FWIW, if I had the $$, at the top of my wish list of USA performance cars of the period would be:
1964 Studebaker Avanti (reputedly good for 140-160 mph off the showroom floor. (I believe #1, doubt #2.))
1950s Studebaker Hawk-small V8, very slow 0-60 (low torque), but would outrun any police from 60mph+
2004 Corvair Monza Spyder (closest thing to a Porsche produced in the USA in that era)
Special note about the Hawks: I think the Studebaker Hawks were the closest the USA manufacturers came to producing a European-style GT sedan. (They were 4-seat hardtops.) The Golden Hawk's small-block, supercharged V8 was almost as fast as the two-seater Avanti of the 1960s, and the lesser (carbureted) Hawks were not much slower. (At least in a straight line -- I won't vouch for braking and cornering of any US car of the period - except, perhaps, the '64 Monza Spyder's cornering.)
There are others on my list:
Performance:
1950s Hudson Hornet (dominated early NASCAR - prized by young males for another reason). Amazing car!
1963 Corvette SS (Only 50 produced, designed & engineered by Arkos-Duntov, strictly for sportscar racing).
1968 Camaro Z28 (
Only the 1968(?) (first year of the option) was a true performance car. The next year, Chevrolet (in its infinite stupidity) dumbed down the performance of the Z28 to make it only slightly hotter than the top-line regular Camaro. The first-year Z28s were truly nasty; subsequent models were relative pussycats, though the trim packages proclaimed that they were still tigers.
Styling:
1955 Chevrolet Bel Air V8 hardtop or convertible (long rear deck)
1957 Ford Fairlane V8 2-door Hardtop (long rear deck). Looked great, and with proper(?) silencers, had a sound like nothing else.