Ok, been out today in the wet to see if the car is much faster since the software updates and the lighter alloys and tyres. Finally got my hands back on the Performance box.
The run below was done in the wet, with just over half a tank of fuel and full interior. The surface starts off level and then goes into a decline half way on the run to the end, but no more than Bruntingthorpe has by comparison. Wheelspin at all 4 wheels to around 30 mph and I used launch control at just over 4krpms.
The car definitely feels better, revs out well to the redline and the pull is much harder.
No 1/4 mile this time though as there is a gate at the end!