With an Explorer tipping the scales at just under 5000lbs, your Expedition is close to twice the weight of a normal car. Not a "little" car, but a NORMAL car. Putting a Warp11 or two in that thing would suck so much power that even the practically unavailable technology of today/tomorrow would be lacking. A generator hybrid setup would be the better choice, but one has to ask. Why would you realistically need something that big in the first place? Come to think of it... how DID Americans get around before the auto companies brainwashed them into thinking they needed 7000lbs of metal surrounding them just to go to Starbucks for a decaf mocha latte?
One more note... a Crown Victoria is a full size car (at < 4000lbs). An Expedition is size XL.