I agree with Mike. While I admit that I've never looked inside a Volvo bumper, I would think that if the bumper isn't lined up at least past of the crumple zone designed to protect passengers has crumpled and needs to be replaced to return the car to it's pre-crash level of safety.

Based on the rules in New York State, where I live, the person that did the rear ending is the person whose insurance ends up paying and Geico is just trying to get you to settle cheap. Why do you think Geico advertises low rates? Not by saying here is a nice fat check to have your car fixed with Volvo parts. If you take a check for "buffing out" (equals cheap paint job in my mind) saves them money.

You may have to fight a little, but you, the injured party, have the right to be 'made whole'. So have a Volvo dealer with a repair shop give you an estimate and then talk to the Geico guy.

And while I am glad you wife is fine, you might ask Geico if they will cover a doctor's appointment so that her developing neck & back pains can be looked at if they balk at the proper car repair. They really hate personal injury claims and might try harder to make you happy with a decent car repair.