i fitted 6.5 inch alpine 's' type in the front using the original pods with lots of stuffing around. the easier way of doing it is basically re making the door pod in mdf. cut a bit for the base then using some thick stuff glued in layers make a 6.5 inch mdf tube cut with a jig saw. fits perfectly it just dosent angle the speaker towards the driver like the factory pod does.
with mine I cut off the back protector bit, filled in the gap around the outer edge (on the back) with bodyfiller, then hacked it up (cut out for fitment and cut off top ridge) to fit the speakers.