i currently have two 10s in my del sol's trunk. there really isn't much of a rattle or anything because the roof has the rubber/plastic junk where it clips onto the rack. the spare tire screw thing rattles on the spare though, cuz it keeps shaking loose. however, i am currently muilding a custom MDF/Fiberglass box that will sit behind the seats and replace the rear panel and storage compartment. it's going to house 3 12s. so, as long as you have the patients to figure out something creative, you can get away with a lot in your del sol.