Although Cindy Williams was cast as Laurie Henderson and enjoyed working with both Lucas and Howard , the actress hoped she would get the part of Debbie Dunham, which ended up going to Candy Clark. Mackenzie Phillips, who portrays Carol, was only 12, and under California law, producer Gary Kurtz had to become her legal guardian for the duration of filming. For Bob Falfa, Roos cast Harrison Ford, who was then concentrating on a carpentry career. Ford agreed to take the role on the condition that he would not have to cut his hair. The character has a flattop in the script, but a compromise was eventually reached whereby Ford wore a stetson to cover his hair. Producer Francis Ford Coppola encouraged Lucas to cast Wolfman Jack as himself in a cameo appearance. "George Lucas and I went through thousands of Wolfman Jack phone calls that were taped with the public," Jack reflected. "The telephone calls [heard on the broadcasts] in the motion picture and on the soundtrack were actual calls with real people. "