Yeah MINI dealerships are pretty anal about mods.

But you can get JCW upgrade kit, which is MINI approved and RMW ECU tune, which is undetectable with the JCW bits and RMW ECU tune, you should get a nice hp/torque figure. Really, though a rear sway bar and sticky tires is all you need.

Check out current crop of sticky tires (note:not meant for winter) here:
http://www.northamericanmotoring.com...blication.html
As for 4 wheel drive MINI, they have been testing for awhile. And ever since Suburu and Prodrive "mutually" dumped eachother. The WRC rally series rumors are that they came to an agreement and are testing a individual MINI parts for the FIA World Rallye Championship (WRC) details here:
http://www.autocar.co.uk/News/NewsAr...llCars/244415/ AND Here:
http://www.rallybuzz.com/prodrive-mini-crossover-wrc/ just wish Colin McRae was around RIP to Pilot the MINI, but Petter Solberg will work as a MINI Pilot.

Also, I wonder if there will be a conflict between the official MINI Motorsport Centre and Prodrive, but doubt it since MINI Motorsport Centre is BMW/MINI owned. Dude, I am so stoked about this , I hope it goes through!