it didn't actually blow up.. just melted the internal of the shifter, blowing the LED light as well.. not a big deal, could've used it still.. but too much work, so I picked up another one instead.
To do it you want to tap into the OBC sensor which turns on your heated mirrors, nozzels, etc. automatically, so your shift knob heats up too.. put a heating element in your shift knob, and line it with something to protect the plastics.
The reason why mine melted is because I was working behind my dash and the trigger to turn it on was not rewired properly.. so in the hot summer months, the shift knob heating element turned on... the combination of heat, and the element, melted the shift knob.. (no fire or anything.) My careless fault really. It's tough to remember what all those wires behind the dashboard does... I have so many little custom things and wires running everywhere.