Reply to "You have a custom rear lid?"

From an aerodyamic perspective and high speed stability, I've seen a number of the open road racers apply a lexan sheet between the sail panels. It helps reduce the big low pressure area behind the car which causes drag. This will not help cooling. I understand the louvers can produce a bit of a compromise. Many of the things that reduce drag inhibit cooling.

You still need to do something for down force. The front wheels needs this attention the most as Panteras in stock trim are known to experience nose lift at speed, but a good air dam, a splitter and a little rake usually solves this problem. A wing or spoiler will do for the back.

There's a member on this board (Dave...?) that did some high speed work with his car and had (dunno if it's still available) this deck lid for sale. Looks like this was designed to reduce drag and produce some down force.

Best,
Kelly