Aside from replacing the wheels, I would SO consider that car in Montecarlo Blue.
An I6 (my preference... likely I4 turbo option, too), manual or SMG gearbox, decent AWD, and that ride height (high enough, but not bro-truck lifted)
Screw the rear doors. Screw the framed window glass in the doors... make it a COUPE, with a hatch.
X6 should have been a big 3-door GT coupe, too, like the 6 suggests it should. But Montecarlo Blue looks fantastic.