Probably a record setter in our rapid product development!  A friend asked if we could do a simple relay driver that would allow a low voltage device like an Arduino to drive a standard automotive relay. Done deal.  The simple "A-Relay-Driver" is an opto-isolated, transient suppressed, flyback protected relay driver that will all your Arduino or microcontroller car project to control a standard high current automotive relay.  All that is techno-nerd speak for not only does this allow your Arduino to control things like serious lighting, it does it in a way that isolates and protects your Arduino outputs from all the nasty things that take place on the car's 12-volt power lines. Fits in a standard relay socket; accepts a standard automotive relay. Requires an additional 12V connection. 

Another RideTron module to empower you to build the coolest custom cars in the world!