They are Earthquake SWS shallow mounts.They are kind of pricey but sound great.We used to sell them in my shop.Pioneer also makes a shallow mount thats not as pricey.They are only 2" deep!
The actual model is SWS8. If you want 10s they are SWS10. I think it stands for Shallow Woofer System. They sound great. They are pricier then the Pioneers, but most stereo shops told me to stay away from the shallow Pioneers. And I had never had good luck with my Pioneer head units, so that was enough for me. I'm impressed with them honestly. Even right now with only one inside it sounds good.
They are Chrysler Sebring seats.They are wider than the factory seats so I don't see why they couldn't build you an enclosure to fit.Souns like you need to find another shop.
The space between my seats was like 9 1/4" or something,so after measuring they were like "yeah,you can't fit a box in there,it needs to be atleast 11" wide blah blah blah to mount the sub in the box and blah blah blah.