Almost everyone starts out too small as far as parts/tool carrier.

If you are running a 1/10 buggy and never plan to expand you can get by with a small flip top(12"x18" or some such) plano compartmented deal.

But anything larger or two cars and up, might as well get something that will carry everything you might want to bring. The farther from home you go the more you'll want to bring.

I use this. Plano 737002