Here in the UK, as I bought mine just before the new registration year came in and the dealer obviously hadn't hit target, he gave me about seven percent off the cost of my car if I bought it before the end of the month.
Seeing as I was going to buy one anyway, I nearly bit his arm off.
What's more, I have it in writing so he can't go back on the quote.
I think 6 months ago was a different story, but at this point, nobody should be paying over MSRP in the US. Dealers are getting more than 2 allocations per month on S5's (and something like a dozen allocations for A5's), and the wait time is something like 3 months, which is tolerable.
I bought mine in Rockville, Md and my dealer pissed me off so they gave e the Audi Care Package for free. It was like a $700 Value, but since my order was 4 Months Late, they actually gave me a deal in a way.