They sound original 😂
Looking to upgrade them all and run some speaker cable. Also next on my list is to figure out what to do with the tv screen which is in the roof lining. It powers up but I think it’s a Jap sat nav.
Presumably you still have the original stereo and dash screen fitted as well?
As Harvo said, the screen quality isn't great by modern standards (and a little small!), but still very usable if you have the original kit in place.
People used to bin them for a pass time, but the original Clarion stereos were actually very good quality for the time, and still sound great providing you've replaced the speakers.
You can plug your av devices in via the av inputs behind the rear seat, and you can also listen to music via your phone, etc. via the lower satnav unit using a standard 3.5 jack to jack auxiliary cable.
Good luck, and if you're okay with ripping dvds, you should consider a media player with av out instead as they're smaller and you don't have to carry dvds around, etc.
If you do decide to change the unit, have a look at Karl's post here: http://forum.elgrandoc.uk/threads/how-to-change-head-unit.62/
I changed all my speakers in my old E50 I used to own with a set of FLi speakers. The sound improvement was great. The Original speakers were all knackered and worn and falling apart around the foam area's. The fronts were easy to fit but as RobP said the rears were fiddly and I actually had to nibble away some of the trim behind the speaker grills in order that I could get the new speakers back in which was ok to do as once in and the grills back on you would never know. Saved me having to remove the entire interior side trim panel which would have bee a total ball ache job.