1. Lamborghini Miura: "Floating" front end at high speed
2. DeLorean DMC12: Way underpowered
3. Jaguar XJ220: NA V12 engine swapped out for twin turbo V6 at the last minute, larger more ungainly car, horrid turbo lag
4. Lamgorghini Aventador: Neck-breaking gear change
5. Any rotary-engined road cars: Worn rotor tips (more so older cars), poor fuel efficiency
6. Vector W8: Came out about 12 years too late but still would've been pretty lousy to drive (still have a soft spot for Vectors though)
7. Ford Mustang (Current gen and numerous tuned versions): Live axle!
8. Noble M600: Steel brakes, potential gearbox issues
Actually most of those are still great, just could be greater
