Urs -
I am not building yet. I want to start this year but there are many other things going on at home which is slowing down the design. I have my engine (Audi 3.6l V8 from the 1990 V8 quattro), Audi 016 transaxle from a 5000, Corvette C5 brakes and wheel bearings, Datsun 260Z steering rack, and Corvette C5 windshield. I am not finished yet with the suspension layout and since I still have time I am still working on the aerodynamics. I still have not even decided if I will put the engine radiator in the front or on the sides! Plus, there is structural analysis to do on important parts like uprights....
That is where a lot of the fun is though - designing!
Good luck with your project - I am always checking for updates.