How can I clean some really really nasty seats?

 

Search-engine pulled up these results:


There are number of upholstery cleaning agents available. Here I used a spray cleaner from Turtle Wax. Simply spray evenly on the seat or door upholstery and rub vigorously. Then, wipe it thoroughly with a dry cloth.
If you don't have a upholstery cleaner, simple laundry detergent will work as well. Just damp a rag with a little bit of water and the laundry detergent, squeeze the excess of water out and rub the fabric. Then, rub dry with a clean, soft cloth.
Don't soak the seat with water, it will cause stains on the seat and mould smell.


Link to website

 

cloth or leather?

 

if they are leather use meguiars leather polish.If cloth you can find many products at your local part store i cant tell you the best product but i can say dont use anything turtlewax