That's a very good idea, IMHO. I've always been very wary of being hit from behind by some distracted driver; even more in the past ten years or so. I always stop at an angle behind cars at a stop light or sign, and keep an eye in the mirror for knuckleheads approaching. Phones
Do you draw the voltage from the rear tail light assembly?
Yes, wired into the rear light assemble.
Lay on your back and remove the little panel to expose the wires and all the rear bulb holders.
Being all-LEDs, the drain is not significant.
Photo hoster took away all my install pix - but I added a sticky, above, of the procedure.
Routed wires to the assembly into the body, here
Stig