So I have this recurring fantasy where I design a simple 12 volt grinding tool using a starter motor with a ferrous metal cutting wheel bolted to the axle. In my dream I have long, coiled, power lead from the motor to a cigar-lighter plug so the tool can plugged into any vehicle’s socket by running the cable in the window.

Anyway, I’ve never actually gotten anywhere with the project, but this guy has :-) Thanks to londonblog