I get a kink in my neck when I do this... how about you ??? ;¬D

Oh! Ok!
Gotcha!
Other's opinions may differ, but here is what I would do.
go to this website
http://www.prowax.com/
Find a dealer near you.
http://www.prowax.com/1_moreinfoform.shtml
Call them and Get some C-49.
http://www.prowax.com/cleaners.shtml#C-54
Or I suppose you could order it online.

A gallon ia around $14 it dilutes 5 to 1, remember that and do NOT think it
will work better if it's stronger. A gallon will last you a LONG LONG TIME.

Now get a and a spray bottle, a good terrycloth towell, scrub brush, a
bucket of fresh water, A cooler of ice cold beer and a radio wouldn't hurt a
thing.

If the seats can be cleaned, this will do it.
You might want to get some (NOT ARMOR ALL)
S-92 Premo dressing. Beeee-cause...... sometimes when vinyl gets a good
cleaning after it has been really dirty for a long time it will get a
white-ish haze over it. It's because the oils are all taken off of it. The
Premo dressing does have some of the nasty silicone in it BUT the difference
between it and armor all is that it will wash and wear off and does not
build upwhen used with a dollop of common sense.
http://www.prowax.com/dress_waterbase.shtml#S-92

You can get a small container that will last a LONG time for under $10.
I use a damp sponge (like a micro fiber sponge) or a piece of an old T-shirt
that has been dampened with water and wrung out  rather than spraying it on.
Dampen the sponge too. Spray the material lightly on the fabric rather than
on your car then wipe it on,. A little goes a LONG ways!

Hope this helps, I've been using this stuff for years and it has always
served me well, of course your mileage may vary.
Would love to have you post your solution and how it came out.

Hmm... this reminds me, I need to stock up again, I am about out of some
things.

Kate