I have 4 trade in guns, all shoot great:
4586- Has some gouges on the slide where it looks like it slid on concrete. Internally, looks great. Slide has a little bit of play, but I've seen a lot worse on many new guns.
4506- It has a couple of shiny spots on the muzzle end of the slide, and the checkering on the front of the trigger guard has something on it that only partially cleaned off, even using a toothbrush and several different solvents. I'm guessing it's paint of some kind.
5906- Almost new, no doubts about it. No wear inside at all, one tiny shiny spot on the bottom rear of the slide near the decock/safety lever.
4006 TSW. Excellent outside, nearly perfect inside. A few holster marks is all there is.
As most others posting in this thread would say, "I have no fear buying a trade in police gun, but I would never buy a trade in police car!". After seeing what was in the back of the prize a friend bought years ago, I would be scared to even sit in one before it was thoroughly cleaned, and preferably sterilized first! He bought it in his wife's hometown in North Carolina, and drove it home from the auction all the way to Ohio without any real issues. Nearly everything mechanical needed to be replaced, and the mice had done a fine job eating on the wiring harness too. There was a nest of little mouse skeletons in the trunk. Eventually, he got it all fixed up and had it painted at MAACO in an odd shade of brown. I don't know why he picked that brown, and he said later on, he didn't know why either. He had it for about 12 years, and then his son wrecked it when he fell asleep coming home from work one night. The 440 from it is now being built to go into his old 79 Dodge truck he got on Ebay. The cop car was in great shape compared to it.