I currently have a ported box that i bought from a small independent shop. It is just too big for the car and i would like to either put it up against the back seat or in the spare (but keeping the spare tire). I listen to all type of music but i want to aim for quality bass, so i was thinking about a sealed box this time around. If anyone has any suggestion or any place i can just buy a pre fab box for the is300 that would be great! Thanks in advance.