You need to shop around if he doesn't want to talk below MSRP, his loss if you go somewhere else. Some other dealer will def want your business even if you do have a discount. I got 1500 off of MSRP + Audi Care, told them I had another dealer that offered me the same but was farther away and I preferred to buy here. They agreed that if some other dealership can do it, so can they! Don't let those guys intimidate you. I got the "no discount" line as well.
I also shopped around and got 1,500 off MSRP in Audi of Bernardsville. Easiet way for me was to send a blast email to all the local dealers and letting them know they each were competing with 1 another to get my business. Make sure the more dealers contacted the better. I only had about 40-50% that responded back.
I own an Infiniti FX so i'm a little biased towards Infiniti and I drove the G37 6MT and although a great car with a more powerful engine the A5 is superior by far. The build quality is superior as is the interior.
I found it drove better as well.
I would get the S-line version if I was you. The one thing about the 3.2L engine is it lacks the torque of the S5 so it does better with the 6-spd.
Here in Chicago, the list price for my order is $49,240 for the 2008 model. No quote was available yet for the 2009 model which is what I'm expecting since the delivery is not until November. I went to seven different dealerships both in IL and out and no one would sell under list price. One dealership was even selling above list price for any S5 they could get a hold of.