The Ford is a very good car. However, I wouldn't touch the Audi for a bunch of reasons.
Nonetheless, it's a no brainer to take the Carrera GT over both of them. FWIW, the clutch does NOT cost $20K but it is still very expensive (w/labor ~$10K) and very
special. You gotta pay to play.
I know a guy near me that drives his CGT several times a week during the summer as well as participating in DE's. Never an issue. He loves it. Same holds true with the other three owners I've talked to.
I think your old man kind of screwed the pooch on this decision...but, hey, it's not my money (unfortunately).