Many years ago I created a series of 1/25 RC Hopper cars using circuit boards of dirt cheap RC toy cars that
proved to be quite effective and lot's of fun.

 


Two 3V relays send the power directly the hopper motor to bypass the rather weak transistors on the 
circuit board. That orange thing connected to the motor is a capacitor to get rid of interference 
with the RC unit.



A cheap micro servo capable of lifting 1.5kg directly connected to a single "cylinder's ram" lifts and lowers the
model lowrider with ease. 



The allu ram connected to the servos arm. It's better to have the ram connected near the center of 
rear axle that way it can handle the weight of the batteries without hanging too much to one side.



Drive shaft for that authentic look. 



Complete chassis with enough room to fit the interior. 3 AAA batteries provide the juice although I prefer to 
use a small 3.6V 
lipo battery and add weight to make this scale lowrider hop like the real thing. 
I swapped the original remote 
control for a new switchbox and connected two momentary toggle switches to 
control the cars motions.