This winter I became obsessed with 12 Volt automotive wiring. I used this power wheels upgrade project to learn how to solder, splice copper and design circuits. I made my own potentiometer thumb control out of discarded RC radio parts and used a $15 PWM speed control ordered online. I found lots of great parts at Active Surplus, such as 12V lead acid battery, the polarity reversing switch, auto relays and cheap LED lights for headlamps. The budget on this project was about $60.