The covers can come off, but there's a lot of 2mm thick metal tabs to be unbent and not much room to get in and pry. Also there's a fair amount of double sided sticky tape holding down fabric tabs, so I'd rather not unstick them.
Most of it is just dirty dust accumilated over time, I imagine from being stored. There are a few light oilly looking areas though. That's what I imagine it is, oil.
http://pages.ebay.com/link/?nav=item.vi ... 16&alt=web
This is what I use at work. It can be diluted a long way. I can't remember what I dilute it to as it's on a mixer system to keep quantities exact.
If you spray this on and agitate with a soft brush then vacuum out.
Works on rugs and carpet too. Just dont got too close or you disrupt the weave.
spray with your choice of carpet/upholstery cleaner and then rince with pressure washer. set the pressure by the end nozzle. you need to push the cleaner out and through but not damage the finish. You end up with a crushed velvet effect if you gung ho it but its very effective.
6th gen Prelude please Mr Honda. RWD 2.4 turbo lude.
I use a vax on mine. Only 4 bolts on each front seat so remove them from the car on a nice sunny day. You can use some autoglym interior shampoo first and agitate any stains then use the hand held vax attachment with warm water only, no detergent, in the vax to thoroughly rinse out the ag shampoo, you will be amazed at the ingrained dirt that comes out. Keep going until the water is clear.