Likely not going to happen. My agreement with my dealer is for msrp. If the V10 came out 1-2 yrs ago, then yes there likely would be some discounting..but you'll never know. In these times, if these cars go unsold, it is possible.
IMAO, I'd work instead on getting them to include or discount some of the extras, such as Audi Care, wheel & tire warranties, clear bra, tracking devices, etc. In this economy, its not unreasonable to ask for a little extra lovin' when you are spending that kind of money on a car, and those are high-profit items for the dealer.