I've just been into Game in the Manchester Arndale. They're doing a little Forza competition. It's a 2 lap race on the Bernese Alps Club Circuit (the one the Ferrari race was on in the demo) in the Veyron (R3, PI of 765 - wasn't it 800 in Forza 3?) on medium difficulty. That means ABS, TCS and STS all on, with auto gears and full braking line, which is considerably more assists than I'm used to.
It's 50p a time, with half going to charity, and the prize for the best time over the two laps is enough MS points to get the DLC, and the next 3 best times get a £10 game voucher.
I had two goes and my best time was 2:55.something. The guy said it was a pretty good time, but I'm not all that hopeful, as I know I'm not that brilliant. Still, the guy only had one A4 sheet of times written down at that point, so fingers crossed.
For the record, the Veyron felt good, but more wobbly than in FM3 - I think I had more trouble keeping it pointing in a straight line.