More specifically......look closely at the lines along doors and fenders. Look at the gap between doors and the body and follow along.....it should stay the same width all the way around. Lines at the tops of front doors should follow straight into the lines of the back doors. Check hood lines and hatch door lines as well, as well as ones on the side of the car that was not hit.
Underneath you want to look most closely at the part of the body that makes up the "frame", such as it is. Look specifically for cracks or wrinkles in the metal. If you see wrinkles, you'll want to compare to the other side of the car, or to a similar but un-crashed Escape to see if it is similar.
Look for fresh undercoating, especially if it's in odd areas like the engine compartment side of a fender well. Undercoating does a creat job of covering metal work that didn't get fixed, or didn't get fixed right, but....keep in mind...it's not a bad way to cover up well done work as well. It eliminates rust and cuts refinishing time in areas that most people don't care much about, including the underside of a car. It may cue you to where welding or straightening was done.
Take a good look at what your tire wear is like, and then start checking every few thousand miles. Look for feathering of the tread, or wear that is to one side or the other.....no longer even across the tire.
And of course, go drive top end.....whatever that is on an Escape....I haven't tried mine yet....listen for rattles, wind noise that's out of line, or suspension pulls or shakes. Speed amplifies everything. Only do this in a spot where it is legal of course

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