Okay, if anybody is Class D, I'm available to battle you. I'm in Mountain Bash, and I'm ready, willing, and able to race at all times.
Is it okay if I use all of my bonuses on one of the first cars? If I start a new car, and I delete a car that had a bunch of bonuses on it, do I get those bonuses back to use on the new car?
Well, actually, you get 2 upgrades per car at Class D, including new ones you buy. Since the new cars have higher stats too, though, it's probably a better idea just to sell most of your old cars and buy a new one. Just make sure to remove all equipment first or you'll lose it!