$10 at walmart for a compact one that will fit in the glovebox will do. not all cars need them. but some do. Powersteering leaks on hot exhaust, or valve cover leak. never know. crazy shit happens.
as for tires, i paid $20 a tire for winter recaps during summer, and 25 per tire in winter. now i got actual rally tires–which are alot more money. the tires are worth it, but i would advise against it unless you are for sure you are going to keep doing this.
smithton is not really a stock/modified class. our rules differ from scca. basically you will be in fwd turbo class. be honest, not many fwd turbo cars come race anymore, unless joe and ryan are coming again, you will be only one. that means you would get paired in w/ all the other fwd guys.
come down for one race and see whats up, and go spend crazy from there 