Morning Jack
Try talking to some of the BMW specialists I dont know where you are but my Brother Inlaw has used a guy in West London (Hayes/Uxbridge) on several BMW's BW Tuning I think. Have a Google and talk to them is what I would do
Dave
I have a friend who built 2 Caterham's he described them as his weekend adrenalin pumps.
My son does have the right idea as he will probably get the beer out of my Garage fridge !!! Cheeky boy