For $20 @ Walmart ,I bought a combo brake-turn-tail LED 12 v lite about 2"x6" To use it on my 6v + grd sedan, I used the white grd wire as the hot wire & the brake wire as the grd. I stuck it to the rear window with a dab of clear silicone on each end. Then it was a simple matter to run the wires behind the backrest to tie into the brake lite & grd.