some more testing, by removing the upper block and the OF doesnt bubble, so Im thinking that over the summer I will leave the upper block off.
next up, lower air dam, the mp5 has a small (2' across) one already in place that I can just hook onto and extend down and out to include the front tires, I have more than enough coro that I may even be able to make a front belly pan, but not sure if I want to use coro for that, Id prefer something a little more durable