[86951]

Shaun low bass waves will pass through anything. You do not have to worry about blocking the sound as long as you are running them as subs. It is the people that buy subs and run full range to them that sound funny if you cover them up. Also the speakers do not last long running full range to them since there are no voice coils.
The 8s probally sound better due to space, a bass wave takes a certain amount of feet to complete a cycle. Like a 15 takes in the neighborhood of 32 feet to complete a cycle at 16 feet it will not sound back but anything closer sucks. 10s off the glass in a 944 might be pushing the limits of the interior.