I did kinda the same thing as BK did, but used a seperate LED light fixture for the turn signals. Also installed a 'Wig-Wag' flasher box in the trunk, that flashes the brake lights from side to side, before coming on solid. Have the speakers and all light wires going through a conector so they can be easily unplugged/plugged back in, when removing or installing the trunk.
Older picture, but this shows the turns...

Black Dog