As you can imagine, a 5 1/2 hole saw is a monster to hang onto even at low speed. I did weld a 3/16" plate behind the tail panel so the pilot bit had something to guide it.
Fab'd up the tail light housings. I couldn't use the factory ones because of all the tail panel modifications and I wanted to slightly adjust their location to fit better with the widened tail.
You can't see it in these pics but there is a rubber seal between the tail light lens and the body.
Ended up adding about 4 lbs extra to the car but didn't really have a choice, in order to use a rubber seal, the bracket needed to be relatively stout. Had the shapes cut with a plasma table and then drilled the holes, just to help with the the weight. LED lights will mount inside later.