I was just talking to someone about their Saabaru 92x. It hit me that that was one of the better joint ventures cars.
As a little thought experiment:

If you could get any two manufactures to join force on a car what would you want?

Volvo safety with Alfa Romeo styling?
Ferrari performance with Kia Price

 

I'd let the Red Bull Renault team go crazy with the aero package on a Mercedes CL65AMG

 

GREAT TOPIC! I love bench racing.

Being a MINI employee, I would first have to go with the BMW M3's motor mid-mounted to an All4 Cooper S Hardtop.

Another good combo would be a Kia/Hyundai Genesis. They are the same company but a 2.0T in a base Kia with manual transmission and decent suspension would be an awesome car.

 

I would like to see M division get a hold of a MINI cause that would be sweet but, I think a Japanese aftermarket company should get a hold of the MINI and do it out. There really isn't very many manufactures right now that I would think could do a good collaboration and turn something out worth a crap right now.