Going to be bored for the next few hours as I am in standby mode with no place to go

So here’s my question:

You have to choose between a car you aren’t allowed to modify ever or one you have to modify to get it where you want it. (but no major swaps, i.e. chassis, body, unrealistic engine swaps etc.). Which do you choose and what car? You have to keep it for 10 years min.