Everyone upgrades with the typical rpm a-arms, heat-sinks, axle hubs... and some go all out and upgrade with a water cooled radiator system, or a custom 4 piece metal front bumper. Which upgrade (be it custom or factory bought) improved your car the most, or maybe that your most proud of? It could be the simple and cheap modification of swapping the A-arms that make a radical change in the performance in you rc, but let us know and maybe throw in a couple of pictures (everyone likes pictures).
I'm proud of my wiring but it doesn't do much for the functionality of the car.
The shocks do keep my car from kicking to one side when i hit the throttle, and are great for the giant impacts.
These wheels extenders are great! I can make high speed turns and I hardly ever flip my lid anymore!