Might not be a bad idea to remove the rear seat and possibly some carpet to see if the floor pan there is wrinkled.
When my son wrecked his Camaro (not his fault and front end) from 30 feet away the car looked pretty good other than a canted RF wheel. Closer inspection showed the firewall was buckled along with the floor pan underneath the passenger seat. It was a total and a pro body man who bought the car with intentions of fixing it just decided to throw in the towel and parted it out.
Impact forces travel a long way.
A single woman who is a friend had a 1996 Ford Taurus station wagon. She was visiting another friend when another person sideswiped the Taurus in the driveway. The doors on the driver’s side were dented slightly, but the doors opened and closed perfectly and no glass was broken. The insurance company totaled the Taurus. Our friend bought the car back and found a body technician that did repairs on the side and had the Taurus repaired.
I had seen the cosmetic damage and thought it was strange the insurance company totaled the vehicle. A couple years later, our friend.told me that her mechanic would not put the car up on the hoist as the undercarriage was too badly rusted. Our friend has a newer car, but said she wouldn’t take the Taurus wagon on the highway but would just use it for hauling things around town. I convinced her that the Taurus was not even safe to drive around town. She then sold it to her mechanic who wanted the engine. The rest of the car was junked. I then understood why the insurance company totaled the Taurus.
In 2005 my wife’s 2002 Saturn Vue was hit from behind. She was stopped, and I’d guess the other driver was doing about 50. When the car was at the body shop I was with the adjuster and the shop team talking about the damage and how they would fix it. I went in the back seat and pulled it up to reveal the incredible damage to the body. You could see the whole car was compromised (unibody). I demanded they total it, and they did. And this was a 3 year old car. The OP’s car is 20!