I want a 3 way set also. I have got some inside info that tweeter may start carrying Focal so I can get them cheap. I made them by taping off the entire area i was going to put down glass. Basicly the entire floor mat and stock kick panel, half the seat and the dash was taped. I used a marker to draw where I would later cut the glass to. basicly the tape transfers te line to the glass. then I laid some hot resin and then glassed the area I wanted the base to be 3 layers deep. waited like an hour, took out the base and tape and cut it to the line. I made a baffle with 1/4 mdf and the MB Quart speaker rings. then I put the base back in the car and used blocks with glue to position the baffles on the base at their to be perminant angles. I played with that for about 2 hours to get imaging and good balance. Then took them back out wrapped the pieces over with fleace to make the shape. the fleace is spray glued on. then I resined the fleece. then I poured resin into the pods untill it was strong as hell. Basicly I used 1/4 gallon per pod on the inside. Then I cut out the back of the pods since Quarts can't be in a sealed enclosure and trimmed off the fleace that overlapped the glass that I didn't need on the back. I usde Bondo to smooth and shape the pods then hit them with black piant to hide that bondos pink color. Then I wrapped them in trunk linear and installed them.
I can't post pics so I will send you the photos through email, just need the adress
Here's a link to the Q Forms universal pod. That might work: http://www.airesearch.com/qlk5001.html
Put your third speaker in the door(?)
They don't make anything for Mazda cars, just the trucks.