Good point. Might only get a 320 for 70k with delivery. As for teh F6, it's fun going sideways...
It did surprisingly well at the skidpan but yeh, I think AWD is stil the way to go.
As for the 320i for $70k, I think you might be able to get a 323i but that'd be about it. For $70k, you could also get a few of the A4 range upto the 2.0T (delivered).
The 370z in manual driveaway is around $68k at the moment, whilst the Golf R will be around $51k driveaway I think (sticker price is $48.5k for the 3dr manual). Much better value than the GTI as it's AWD and has a much higher tuned engine + better trim/equipment.
I wonder why the OP has picked a budget of $50k-70k.... is it a new P Plater? Sponsored by parents? If that's the case, chances are they aren't an enthusiast so we shouldn't bother with suggesting cars aimed at enthusiasts (e.g. STI, Evo's, etc) and stick to the cars which offer badge appeal.