The stealth box is a perfect solution. They won't let you put your subs in there but they will let you spend mucho bucks on a touch screen HU? Umm...thats pretty stupid imo. They must feel great that you're dropping hella cash on your stereo while they shell out your car & insurance payments. Could probably pay for a couple payments with the money you're dumping into the HU alone.
You will probably get in more trouble with the tinted windows than you would bumping your 15s. In my city, tint is a cop magnet. Especially on older sports cars that they know young kids drive...
Think you should negotiate with your rents on the above because it's idiotic.