2010 Mercedes-Benz E-Class Sedan E550 4MATIC 4dr Sedan AWD (5.5L 8cyl 7A)
The trick with these is to find one that has not been messed with - either by poor mechanics or their owners - to minimize the potential gremlins in the system. This includes oil changes "helpfully" done by used car dealers; invariably they'll use a cheap Chinese filter that will collapse and disintegrate, with expensive results. The car drives we well as something that rolled off the dealer lot for 80k six years ago should. Smooth, powerful, settled, with a staid sense of calm throughout. Punch the gas, and a little burble indicates you're probably way over the speed limit already; the car has a sub 5 second 0-60 time.