How do I wash a car seat cover?
Remove the Car SeatRemove the car seat cover from the car. Remove any snap-off metal pieces from the car seat before washing.
Launder the Car SeatPlace the car seat into the washer if the car seat instructions recommend machine washing. Place the car seat into a sink or laundry tub with cool water and 2 tbsp. of laundry detergent if you must hand wash the item. Machine wash car seats with cool water and regular laundry detergent on.
Rinse the Car SeatLaunder the car seat normally in the washing machine. If hand washing the car seat, rub in the soapy water, empty the water, and rinse with cool water. Wring the excess water from the car seat. Remove the car seat from the sink or washer, and hang outside to dry.
Source:Shopping Cart Cover Store: Car Seat Covers