Geez I remember my dad's Toyota Camry would start shaking at just 140 km/hr (87.5 mph.. holy crap maybe I was about to time travel). Many cars, and especially most drivers, just can't go that fast safely..
My first car (an '87 Subaru DL, which I had in 2000-2002 IIRC) started shaking between 70 and 75 MPH. My parents regarded this as a feature, because as a new driver I really had no business going faster than that. They were probably right.