Hey Mike...
My parents have a VW Passat 1.9 diesel engine and is a car for highways..When i drive it i still drive drive like a Frontera...Up to 100km/h or 65mph...I am not a speed guy type..My freedom come when i am on offroad. ...I am pretty confident that on usual roads you can give an Mercedes coupe AMG and still not speeding with it but i will throw it next day and get my off road car back...Mercedes G class on the other hand i may actually keep it
Still waiting for more input to get a more ideas on what will i expect...