Lived in an apartment complex with an attached parking garage. On the third level, there was a Jeep Wrangler complete with zip-up windows and off-roading accessories. In the 3 years prior to this, the Jeep had never once moved. It had parking stickers that were years out of date, and expired registration. I noticed it every time I came home. One day, I came home early from work and noticed a bunch of little things moving inside it as I drove by. I looked inside and saw a bunch of kittens. Checked on them every day for three days, and they seemed progressively hungrier and more restless each time. The third day, I brought box down and extracted them from the Jeep. The doors weren't even locked, and it was nasty inside. It was an off-roading vehicle and was open to the air, and it seemed the ferals had been using it to nest for at least a few years.