The Mégane II Owners' Club

I'm having problems with my front drivers door speaker ( i think it's water that's messed up the speaker) and was going to replace the fronts and tweeters with the Pioneer TS-Q131C's that, from reading the forums seems to be the best. However, The rear drivers side is now making a farting noise, so it's time for the whole speaker system to be replaced i think. What i need advice on is this:

1) is there a full speaker set i.e front, rear and tweeters that you can buy that fit the Megane, if not does anyone know the max depth of the front, and rear speaker hole so i can mix and match? (Ideally not too expensive. <£100)
2) Is there a definite way of ensuring that water doesn’t ruin a new pair of speakers - I’ve read 100's of posts RE water in drivers door, but I’ve yet to find mention of a product or DIY fix that is 100%.
3) is it easy enough to remove the rear speakers, front look easy but rear set look a bit more tricky to get to.

Any help would be great.

the doors are easily modified, i had 2 mtx road thunder components in the front doors. all i had to do is cut a bit of the plastic away to allow room for the magnet to fit in, although i did have to grind/cut off 2 of the wings on the speaker that are used to secure with screws. easily done 5 minute job and far better sound... make sure they are 13cm/5in and cost around £60

I would recommend MTX as i have all MTX gear amps, speakers etc atm but just bought a set of pioneer TS-C13PRS components but i have to do a full door re build to fit the magnet for these in, so far they seem good enough.