The Pontiac Fiero is one of the most (in)famous cheap cars with Ferarri kits. Hell, GM knocked off the Testarossa (or Berlinetta Boxer, depending on who is arguing) for the vanilla body design.
I had a Fiero back in 1987 when I was 16. It was really a crummy car, reliability-wise, but so fun.
Well yeah, you can't goose an iron duke and expect it to run fine. You know the engine was running a quart lower because of a smaller oil pan? I had an 87 Celebrity with the same engine. That 2.5L 4 banger was great but slow.
The Mera was a Ferrari 308 based Fiero rebody that was sold as a dealer option. You could get a zero mile fake Ferrari just by checking a few boxes and doubling the price of the car.