Using a 560SEL's frontal area and drag coefficient, actual top speed with the twin-turbo M117 should range from 220 - 230 mph on that particular setup. It would be ready for liftoff, methinks.

I wouldn't drive any car that fast, anywhere. 100 - 110 mph is enough for me, sustained. I've gone much higher (briefly), but the scenery moves that much quicker, and you really can't make split second decisions when you're traveling at velocities past 160 feet per second, let alone ~ 400 feet per second (OMG). What if your tires fail? What if a medium-sized FFC is sun-bathing in your lane? What if you lose control? This is what: