Vintage Cars: 70 olds cutlass, olds cutlass, automotive upholstery

Question
What would be best way to clean the seats and seat belts. I do not know the fabric of the seats but it is not leather or vinyl. I was told that i can take it to a carwash and spray it clean and then let it sun dry.

Answer
You have to be very careful when cleaning upholstery in older vehicles.  Materials manufactured 40 years ago may not hold up to modern detergents, not to mention what factor age has had.  If the soil level is light, try something mild like Woolite.  If that isn't effective, then there are automotive-upholstery cleaners available at your local auto-parts store.  I would NOT take it through a car wash; you'll never get that level of moisture out of the seats, which would lead to all sorts of problems (rot, mold, deterioration of the foam, etc...).  And you definitely want to clean it when you can leave the car open to dry out completely.