I have set the bends at 7 degrees as I read that was the generally accepted the maximum angle for a diffuser without any interaction with the spoiler.

The good thing is, if you look at the diffuser, I have used extended tiebars on the edge connected to the chassis, this allows me to adjust the angle to whatever I choose with a turn of the bar, so we will try a few different angles with knitting yarn to see at what angle the air detaches from the diffuser.

If also I decide to shorten the diffuser then ill be able to run it at a steeper angle as the spoiler will be able to drive that angle

We have already sorted keeping the air under the car, along the length of the body there are rivnuts put into the chassis, we will use ali angle bolted into the rivnuts and then thick rubber sheet bolted the angle, this will be similar to the 70s f1 cars, they will rub on the floor to find there 'natural' ride height

Ive encorporated this from the front wheels back with no gaps at all to stop the air getting in, also the rear wheel wells are generally high pressure zones so ive removed the inner arches so the air can vent up and out of the clam rather than risking it pushing itself into the underfloor.

I just havent bought the rubber yet, but i think they sell it at b&q and according to wind tunnel data on an exige it should give me about 4% more downforce.