[Stewie]

Former insurance adjuster. The buckle in the rear quarter means that they will have to put your on a rack ("frame alignment device") measure where everything is at currently and then apply force to pull everything back into spec. Once they've done that they can assess if the rear quarter can be repaired or if it would need to be replaced. If it needs to be replaced they will cut it off the car and weld a new quarter panel in.

Getting it "pulled" by a good shop is going to be the key here. If the shop doesn't do a good job, the trunk won't align properly and you could end up with a leaky trunk. Check the trunk with a hose while at the shop,after repairs.