That would be awesome, pretty much any older car or truck with a decent running modern turbodiesel would be awesome lol. It would be super cool with a C-body because normally the only way to make them really move is with a big block and then you average 12 MPG; top speed would be lower with a diesel but everyone knows what a tuned Cummins can do in the torque department and you'd be getting double the fuel mileage easily.