sorry to hear your bad experience with Pioneer cosmo. i for one have had many pioneer head units, and never had problems.
this time round i went with an alpine, and there isent that big of a diference between there performance.
the empty plastic pockets are usualy designed for multiple car models (and manufacturs). the one i got at my local car audio shop was $20 and works for some 20 diferent cars.
oddly enough, i could not have the pocket on top and the HU on the bottom as i would have liked due to some dimension diferences.
also, the top right screw hole for the bracket (where it connects to the dash, not the hu) needed to be "trimmed" to fit back into the dash. i think my alpine is just slighty wider then the factory unit.
the thing i found really neet, is the bracket holding the factory hu has angled cut outs so the new hu's cage can be attached. just bend out the clips on the cage, around the cut outs on the bracket and your good to go!
once the dash trim is put back on, you cant tell at all.
very happy with how easy the install was, including the time spent on the wiring harnesses it took me about 40 minutes to get everything squared away.
next step is running power cables for the amps, and figuring out how im gana get my a/d/s 4" component speakers in the front doors.
perhaps on sunday.