Several years ago I was taking my classroom pet snake (ball python) home for Christmas break. I'd forgotten my portable tank, so just put Caicus (the snake) in a basket and draped a rug over it. I stopped to get gas, and when I got back in the car, I spied the snake, or the last 5 inches or so of his tail, in the floor on the passenger side. He'd already found a place up under the dash to squeeze most of his body. I had his tail, but was afraid to pull too hard. CRAP!! Keep in mind that this was mid December. I left a lamp out in the car the first night (all night), and tried a mouse in a little cage the next day, trying to lure him out. No go. We had a severe cold snap that lasted a few days. Within 2 days of school resuming, I was driving to school with windows down. I had to pay someone to disasemble my entire dashboard to get poor Caicus' decomposing body out
I tried every deodorizer under the sun (some of them worse than the rotting body smell) to get that smell out. Eventually it went away. At least I didn't have to worry about maggots though...