What exactly do boost bottles do for your car? and where can i find some? also, is there such thing as nos for r/c cars? like a fuel addative? thanks

What do they do, very little if anything. They idea is that it increases the size of the crankcase for more boost pressure when the intake opens to force more fuel into the combustion chamber. Tower Hobbies and your LHS. Yes, it's called nitro. More nitro more power.

thanks