Thanks to @Teghogh deal. The S6 wasnt even on my radar. Returned a 550i and was looking at getting a 740/750i demo but unable to get something hacker worthy. Wasnt able to replicate it on a brand new unit but I was able to close the following:
2018 S6 Premium Plus Demo
Miles 5995
MSRP 83865
Sell 69165 (18% off)
Rebate 15000 (35% off)
Acq fee 895
Audicare 1179 (added with the to aqu fee - Residualized) - came out to $360 when residualized versus buying upfront
RES - 36k/10k miles - 47.93% (adjusted for miles and audi care bump up)
MF 0.00220
MSD - $6750. Pay for 10, but it applies only 9 as per Audi FS? I didnt get this but whatever.
Pre-tax Monthly Payment: $614
Monthly Payment with tax: $673
Drive-Off: $1,416 + MSDs
I had a very tough time replicating my original deal though. I talked to 10 plus dealers near me and no one could match it including the dealer I bought it from. Finally I got a call today from one of them that could do 28k off a car with 1k lower msrp
S6 is WAY better than the previous gen 550i. And this is coming from someone who is die hard BMW fan. The S6 is so much faster and responsive. Im not sure about the new M550i though.