Speaker size for 1997 jaguar xk8?

the speaker assemblies in the rear are kind of strange, there is a 6.5" mounted in a box with a tweeter of some sort inside the box. the 6.5" is easy enough to replace with any off the rack speaker, you have to take out the entire interior panel though and it's a bit of a hassle until you'e done it a few times. the door speakers are also 6.5", but the space is much tighter, so the speaker you use may need to be rather slim. then there are tweeters up on the dash and also in the corners inside the side mirrors, not sure what size they are. I just recently had my whole system rewired, with new tweeters on the dash, and a new pioneer stereo w/ iPod jack, about 300 bucks total for all the work and the stereo head unit, though it could be higher depending where you live and what kind of shop you go to.