I already did it several times... I made PLENTY of mistakes, but I seem to have found a steady-state, now. The one that finally worked for me was a 3 Ohm resistor (from VLEDs) screwed to the metal behind the tail lights. The resistor went across the bulb wires, NOT inline. On the drivers side, I had to mount the resistor behind the metal, or else the reflectors wouldn't fit back in place. The factory flasher then worked normally.
Total parts list:
2x 3ohm resistors (VLEDs LR_350) (back)
2x pirannah 1156 yellow towers (ddmtuning) (rear turn)
2x 1156 yellow (autolumination Matrix II? 321led) (front turn)
The DDM towers don't fit in the front turn signal sockets, which is why I went with the autolumination type instead. Otherwise, I do NOT recommend autolumination.
Other:
2x pirannah 1157 red towers (ddmtuning) (rear brake)
2x pirannah 1156 white towers (ddmtuning) (rear reverse)
4x 6k SMT 194 white (vleds 194_4_RB_W_6K) (horns and fogs)