Yep... I asked that question of the email contact at Audi USA. You can get the TT RS via ED and the standard percentage is 5% off the MSRP (but final price is up to the dealership).
One of my local sales guys said "Well... the TT RS is a very sought after model... they usually don't give the discount". The other dealership said "It's 5%... we don't mess around like that". Guess which one I went with.