A mud flap mounting system for connecting a mud flap to a mud flap mounting bracket of a vehicle includes a mud flap group and a mud flap mounting assembly for connecting one mud flap of the mud flap group to a vehicle mud flap mounting bracket. The mud flap group includes at least two mud flaps, each comprising a sheet of flexible material having a top edge and defining at least two mounting openings, each mounting opening including a bolt hole, a first slit and at least a second slit, said first slit being a severed portion of the sheet with virtually no loss of material and extending from the top edge to the corresponding bolt hole, and the at least a second slit extending outwardly from the bolt hole. The mud flap mounting assembly includes a pressure plate, a spring member, a bolt with a head and a shank with a distal end, and a tightening member. The shank extends through the pressure plate, mud flap, bracket, and spring member, and the tightening member engages at the distal end of the shank to compress the pressure plate, mud flap, bracket and spring member between the bolt head and the tightening member. Each mud flap of the mud flap group bears at least one of indicia and an image.