Use 1Z Einszett Deep Vinyl and Plastic cleaner with a gentle upholstery brush, found on the website of one of our forum sponsors. Ultima Interior Shampoo would also work well and be gentler. Also pick up some microfibers if you haven't already.
Top that off with 303 Aerospace protectant, or, if you can spring for it, Ultima Interior Guard Plus- which will last a long time. Chances are the discoloration is oil or something of that sort.
Top that off with 303 Aerospace protectant, or, if you can spring for it, Ultima Interior Guard Plus- which will last a long time. Chances are the discoloration is oil or something of that sort.