The new RGM back box, plus learning how to fully cancel traction control, as well as optimising the throttle response, got the car down from 15.7 to 15.4 on repeated runs. Not bad - now only 0.5 slower than my old Lumina. But not sure which of the above caused the quicker time - maybe a combination of all. Now adding octane booster at every fill - Zeemax confirmed its just the kak local fuel, and some BM's react worse than others. All of AA's recently fitted parts made no difference, but very welcome on motor plan. The exhaust now sounds totally insane - We re-installed the butterfly flap in the right tail pipe, but now sits deeper, and i think this is giving it the Lambo type roar. Hoping to do the next run on semi slicks. Difficult to control the spin with tiptronic. Would welcome any advice. I still need to find out what the disconnection trick is.