While I agree there is no substitute for cubic inches, there are some exceptions that hit the nail on the head. I used to drive a '76 Datsun 280Z, that was one fun car, loved running at 85-90 MPH all day with 160,000 miles on it. Now about Audis, I have a '98 A4 Quattro, 22 years after the Datsun 2 seater was built, a 4 door sedan has almost idential performance at a reasonable price.
I do agree that when it comes to ultimate convertables it is hard to beat old American iron when you take everything into account.