With mud guards, mud, snow, slush, and other road debris are kept within the vehicle's wheel. The more debris being blocked from damaging a vehicle's finish, the lesser the likelihood of paint damage and rust or corrosion problems. Although they are commonly called mud flaps, mud guards and splash guards, these rubber mats also help deflect loose gravel and excessive rainwater. Thus, mud flaps may certainly prove handy during heavy rains and other extreme driving conditions.
Like many other after-market vehicle accessories, mud flaps have now become popular means of self-expression. Most automotive supply stores sell a variety of mud flaps which feature cartoon characters, famous logos, artworks, quotations akin to bumper stickers. There are even some companies who actually manufacture custom mud flaps with their name and contact information on it.