Foams- Order at least 2 thick T-bars and 2 thin T-bars ($5 each) along with 3 sets of .020 Associated springs($2 each). Also get yourself 3 sets of differential rings($1.50each pair) and enough diff balls to go with it($7 for 100). Get two 100t spur gears($4 each) if you run 64pitch if they don't stock those. Buy a backup screw set if you can and a set of "lower" front arms ($2) for the "revolver" front end which is the one that comes with the kit. The kit tires are Greens so make sure you have a set or two of purples for the front and Grays for the rear. Also get yourself 2-3 of the Flanged bearings for the diff. I think they are 1/4 x 1/8 but I'm not sure ($5 each). This is only if your hobbyshop doesn't carry these items. Whatever items they carry don't sweat the rest because you can buy them as needed in the future.-Dave