Okay, all I need to do is win the lottery.
but I get my Mk II shell hunky dory, except for the rear subframe...
Then I buy
this, and something like
this - can you see where I'm going?
I then use a front subframe modded to go in the rear of the mini. I end up with a tuned hog engine in the front with the cam covers just popping through the bonnet like a GTHO shaker hood

and a five speed
plus reverse (rare in a bike-engined car). The weight distribution is perfect, the engine sounds superb and unique in a 4 wheel vehicle. Plus I don't have to worry about oil surge (again another problem with bike engines in a car) as the engine's dry sump.
Only complications are the drive shaft and rear axles but someone must make them. If the direction of the transaxle is opposite to the engine, I 'just' flip the diff. Note that Harleys (being still in the stone age) run separate motors and gearboxes, so you don't end up with 30 forward speeds.
Win. Win. Win.
I'd do it myself but I have neither the time nor quite enough money. So I'm tossing the idea out there so someone can build the coolest mini the world has ever seen.
You're welcome.