I wouldnt bother with the Mazda 6, Its pretty much the exact same thing as the Mazda 3, but a luxury version, and since its heavier/longer it doesnt handle as well, But its still a very nice car, But you wont be able to do crazy things like U-Turn while staying in the same lane (Uhhh...not that you should do that, or would ever need to lol) Audis are pretty nice though, Ive heard they are really expensive to repair though and hard to find repair shops (I think Audi and Volkswagen are kind of merged and we had 2 volkswagens before and that was kind of the case for those cars too) Mazda 3 probably has the most "upgrade potential" though, specially for drift racing......which you shouldnt do either lol