Front: 4" mids & 1" tweeters, but you can go up to 5.25"
Rears: 6.5"
You'll need to get speaker adapter rings to fit all speakers as they're on a 3 point fixing. You can make your own from MDF or buy them from the usual places. Adapter rings for the front are usually designed to take 5.25" units.
The rear speaker panels are a bit tricky:
Prise up door sill trim starting in the middle. It is held in place with about 6 metal clips along the length, and by the other trim pieces at each end.
Once you feel all the clips are free, pull it up in the middle and you should be able to free each end. The footwell end is locked to the kick panel but should slide out with the trim elevated. Check for clips that have come away from the trim. Pull them out with pliers and slide them back into the sill trim.
Remove base of back seat. Flip the base up and push the two retaining bars towards each other to free from the bodywork.
Fold the back of the back seat down flat.
Starting at the base of the door pillar, pull the panel free, working your way up to the top of the panel. The panel is held on by more metal spring clips.
4 clips up the door pillar and 3 along the top.
The top ones are the trickiest and be careful not to rip the panel by pulling on it too hard.
Open the rear window and pull up the window rubber. The use of a pry bar does help with the middle clip.
To release the back clip work from the seat belt upwards.
Carefully lift the panel up & out, making sure you unplug the rear speaker first. (on te drivers side you need to unplug the interior motion sensor overirde).
It is common for some of the clip mountings to come away from the rear panel. These need to be hotglued back in place. Again check that each mounting has a metal clip still attached.
