My favourites - seatbelts and headliner. I've forgotten how to clean these. The seatbelt seems to "absorb" the chemical I sprayed on naturally, and I know headliners are delicate and also tend to "absorb" chemicals. The seatbelt is just grimey and the headliner has splashes from drinks and reminents of dog hair. I've got a steam cleaner and a Bissell. So what's the trick to cleaning these two tough areas?