Easiest way, is just remote start it. The car starts, so does the PC. Whe I see my car, I push the remote three times, the headlights flash, and it starts up. Whe I get in the car, music is playing.
It won't go off by accident too easily because it is 3 pushes within a short time, so the possibility is reduced. Even if it does, it just wastes a little gas for 10minutes then shuts off. The PC is only on when the car is charging the battery.
My remote start only cost me like $50 including shipping.
Seems the more logcal way to go seeing as how you get many more options for a little more money, and you don't have this keychain dongle that only does 1 thing.