subs in rear sidewall

Im sure that any of u that have ever stripped the interior out of your mazda know in the extended cab that there are two alluminum pannels in the side walls that are about 16 to 20 inchesa if i remembwr correcly i wonder how well shallow mount subs would work there

You should fiberglass a small enclosure in each side panel, a shallow 10 in each side would be the biggest I would go. If you try to mount a woofer to that metal without bracing it or doing some kind or reinforcement you will be disappointed all your going to get is some bass and a lot of metal rattling. I too am licking around the idea of putting subs in the sides.

if you do not have subs in mind i would suggest poweracoustik shallow 10. i have a shallow 13 in the matching box and pioneer 760 amp in my rec cab behind pontiac sunfire buckets. sound quality is great and bumps good.

Shallow 10's would be mint!
I've got my 6x9's sitting in the same panel, reinforcement wasn't needed for those... though I boxed them out a little for mounting with a bit of mdf (as you do).. the seats still sneak down past them.
Sony xplods from back in the early 2000's, were supposed to be for my Capri but the 3.0 Essex was sound track enough!

Any tips on volume for a 10 inch there Col? Reckon dude could make a sealed unit in there?
Do it do it!
And then tell us how ;P

I've got 2 8" subs on each side in fiberglass enclosures. I built boxes into the side of the truck to utilize that airspace. Check my pics out:

I took the plates out and made masonite board plates and mounted 6x9 in them instead, gives me alot more midbass then what the factory 6 1/2 speakers did, then i have a 12 in a vented box for lows.