Okay I will be rude and share the outcome locally.
MB ML63PerfPack 585bhp
Aero 8 Coupe 390bhp
Aero 8 S2 340bhp
1315bhp.
However I do have a cheat planned. The 5.5L V8 in the MB is known for taking a bit of tuning. A company called DMS in Southampton offers a 720bhp/690LbFt upgrade. Totally unneeded even at 2000+Kgs but what the heck if you are going to be silly you may as well go the whole hog. 1450bhp!
Just think of the petrol.
Alistair, if you're thinking about remapping the Merc have a chat with Ray at West Tuning, Thruxton, he's one of the top guys for this kind of work.