that was done on cannonball run ages ago!! :p it was roger moores aston martin that had it... what a great movie that was lol better than transporter thats for sure..
OP your best bet is either check were the wire goes from the switch or a cheating way is if both the switch and spotties were done at the same time (therefor it was for spotties) it will more than likely use the same type/colour/brand of wiring, if it was a DIY or a job done on the cheap

