Right. I have the answer.
1. Buy a decent titanium silver M
2. Swap all of the body panels/parts. And I mean all of them - wings, wing mirrors, doors, skirts, boot, front & rear bumpers, roof etc.
3. Except the bonnet - get that corrected / resprayed
4. Swap the mats over and the steering wheel, plus any other bits that make your car 'yours'
5. Don't forget the stubby :wink:
6. Sell your car.
If you do this you will have transplanted all of your car that visually & emotionally makes you proud about how mint it is onto a car that is totally M - engine, steering rack, chassis, suspension, driveshaft, gearbox, diff, suspension, exhaust, brakes... For about £6k and a respray. Only downside is funding the M up front. But as yours is paid for, get a bank loan to bridge the gap, pay it off as soon as you sell yours.
Sorted