then you would be worried about every little noise it made
I wouldn't buy any car that cost 20k, then you have nothing left to mod with.
Barring project cars, maybe a G8 GXP M6 if you can find one in that range. Probably from a private seller. Also Z06 Vette, 2013+ Mustang GT, CTS-V, 03-04 Termi Cobra come to mind.