MC says do not use 409 or Fantastik, see below. I highly recommend Lexol Vinylex, which cleans and protects. It's similar to 303. For stubborn spots, hit with Mr Clean Magic Eraser, followed by Vinylex or 303}.
ACCEPTABLE UPHOLSTERY CLEANERS
MasterCraft Vinyl Dressing
Vinyl Finish Vinyl Cleaner
Dish Soap (such as Dawn or Ivory)
303 High Tech Fabric Guard™
UNACCEPTABLE UPHOLSTERY CLEANERS
409 (it states not for use on vinyl!)
Top Kote Sealant
Son of a Gun
Orange 88 Degreaser
Turtle Wax/Tar Remover
Any product not listed above in the list of Acceptable Upholstery Cleaners!