i've got the pioneer 4 ways in the front (Pioneer TS-A1780R
6-3/4) and rear (Pioneer TS-A6880R). they sound freaking awesome. i also installed foam baffles behind all of mine.
BTW go to
www.crutchfield.com if you need the adapters for the speakers.
few tips for you:
the rear pillars just pop off. all you have to do is work your hand behind them and gently pop the tabs. the doors are held in place with several screws. AND i think they also have to torx 30 screws under the arm rest. (its been over 6 months since i did mine). you will need a panel tool to pop the snaps in the front door too. you might want to spend the $17.00 on a subscription to
http://ptdoityourself.net. they have some exellent do it yourself articles on altering, and moding your pt complete with pics.
Rear speakers: pretty straightforward. BUT get yourself an offset screwdriver!! i wish i had one for mine. the bottom screw on the speaker is hidden behind a trimpanel. and its a PITA to get to!
front speakers: same stuff - straightforward install.
BUT BUT BUT:
those of us with 2004 cruisers and up have discovered that the cruiser has different harnesses for the front door then in the back. i had to have my front speakers permanently wired in place by a friend who ownes a car audio shop. don't know if this has changed much.