for parking lot practices, i would recommend rp30 tires. last a pretty long time, and are the stickiest you'll find with consistent traction through each run. for rubber indoor racing, rp30 tires are again the favorite choice of most racers. for both, i would get the premounted ones and not worry about the inserts. for tire traction, none or something like SXT for parking lots, and whatever that is popular/allowed at the track for the indoor track.
instead of buying upgrades, when your good enough that your car is holding you back, not your driving, i woud personally get a new car altogether. it's much better, and since eventually you'll most likely get one anyway, instead of buying the up grades then moving to a new car, just get a new car, which is much cheaper for performance. also, if doubting that and not enough bank money,stock car get an older xray car or something for $100, which will be much faster and cheaper than upgrading your stock car.
here's a link to an example of a good xray deal.
http://rctech.net/forum/showthread.p...highlight=fk05
here's a good book for chassis set up. it's called the xxx main chassis guide, explains what every adjustment is, does, and how it affects handling. tells you how to fix over steer, under steer, etc. great book.
anyway, i hope this is helpful to you.
- viper55