This gave us a new one today. Absolutely certain it had a broken left rear spring. It was water intrusion into a blown shock absorber that froze and held the car at full compression. Bad shack was known, only had one in stock earlier and other was waiting for better weather.
New springs installed anyway along with the new shock.
I’m going to label those old springs and shelve them in case the replacements are too stiff. 2 more coils, larger OD, and thicker. Have to be close to 20% more spring rate by eye