Hi thre charles,
Well there 2 ways that you could go in to somewhat giving the M5 more of a run then just 1st gear(maybe to 3rd)
1st is the Vortex supercharger which puts out 250hp @the wheels or get a 10 psi pully and bump it up to 295 @the wheels!!! Price MSRP $3500 plus 10+ hour to install
2nd is to do the 3.0 conversion, Sho-SHop is the only one selling the block prep and ready to drop in , startting at $1500. but adding some more mods will jump it up,(for the price of the supercharger, I'm sure u could fine tune it) David Z ran a 14.1 in the 1/4 mile. and is working to fne tune it to the high 13.
These are the real only 2 ways (besides the all NOS) to really get the power. Oh ya the tranny won't beable to handle all the power so you going to nedd to install a Quafi limited slip.
Just my 2 cents
