In 1958 Cepek purchased his first Land Cruiser. He now had the means to travel into the desert and to explore the Baja California coast. He and his wife along with their small son, Tom would spend weeks in Mexico fishing and camping. Cepek also started participating in group drives into the California desert. On these rides he saw the need for wider more durable tires for the off-road vehicles and began utilizing tires marketed for farm use. He had Armstrong Rubber make him tires which he outfitted his own Land Cruiser with. Soon his fellow club members wanted some of the new tires too. Cepek supplied tires to his friends and foresaw the demands for the tires among the larger off-road community as well. He took out and advertisement in Sunset Magazine and stocked his one and a half car garage at home full tires Armstrong made for him especially for off-roading. In 1960 he took Dorothy by a barber shop for sale in South Gate and asked if she would mind if he started an off-road tire shop in the space. She told him to take a go at it and soon he out grew the space, just as he had his garage. In two years time he was able to leave his job at Westinghouse and he moved the business to an old fire hall down the street. In addition to the tires he began selling all manner of off-road equipment from after market products such as shocks and suspension systems to camping gear. People would come from as far as the East Coast to purchase their off-road supplies from Cepek. The business eventually grew to 15 stores and three warehouses, as well as a flourishing catalog business. Through the successful growth of his business and as an active participant Cepek became involved in the organized growth of off-roading as a sport. In 1966 Cepek joined Ed Pearlman and two other teams to try their hand at setting a new four wheeled record racing across Baja. Pearlman and Cepek drove a Toyota Land Cruiser with a Chevy engine as did Claude Dozier and Ed Orr. Bruce Myers donated a Myers Maxx buggy for the press vehicle, driven by Drino Miller and John Lawlor a journalist. The men faced a multitude of technical difficulties yet all completed the course. Orr and Dozier crossed the line into La Paz first with a time of 41 hours and 45 minutes. Pearlman and Cepek came across the line in 56 hours. It took Miller and Lawlor an additional 10 hours to finish with a time of 66 hours. During the course of the race and conversations with Cepek, Pearlman came to the conclusion that there needed to be a more organized form of off-road racing. Once back in California Pearlman invited a group of friends to his home to discuss the formation of an organized racing association. There Pete Condos came up with the name National Off-Road Racing Association (NORRA).
NORRA organized the original Baja 1000 races. Cepek raced in the first three events himself. He also became involved with sponsoring other racers in whom he saw potential talent. Some of his sponsored drivers included fellow Hall of Fame inductees Larry Minor, Rod Hall and Drino Miller. He also sponsored Carl Jackson who raced his jeep with great success at the Riverside, California track.
Cepek passed away in 1983. His son Tom ran Cepek Tires until 2000.