Depending on the material your car seat cover is made from, the answer may be yes. However, most car seat cover makers advise against machine washing because the cover may shrink. All non-sheepskin car seat covers can be spot cleaned with mild detergent and water, taking care to blot up as much moisture as possible. If you have sheepskin covers, you can remove the cover from the seat, spot clean with warm soapy water and allow to air dry away from direct sunlight. If the problem area is large, take the cover to a furrier, or a dry cleaner who specializes in furs.