There are a few little sheet metal nuts that hold them on. If it's an sx/4 or a kammback grab the rear caps! They are very hard to find and highly sought after.
Because the car was on the ground with no front wheels and it looks like it hit a pole or something bendig the bumper, I was unable to get at the bolts. However I was able to grab a nice intact, unbroken drivers side headlight bucket. The passengers side was also very nice and I wanted to grab it, but they were closing in 15 minutes and I didn't want to hold them up. Still want to grab it but not sure when I will have the opportunity to get over there again.
I'm well aware of the rarity of parts for SX-4's and Kammbacks, unfortunately there are no SX-4's or Kammbacks. There is a blue wagon (84 I think), a Two Door Sedan, and a Concord two door sedan. All three are pretty trashed, but there are still a good amount of useable parts.
Also, last time I was there I noticed that the two door eagle had an okay set of rear floor mats in the burgundy/red/maroon interior color. At least one had a tear in them and were dirty, but looked useable. Would there be any interest in them? The front floor mats were WAY to far gone since the windshield was long ago removed.