From the comments in IMDB reviews:
“Von Dutch” Howards extensive artwork throughout the movie, including the opening credits. Bud Ekins’s appearance riding the beautiful Triumph 500 Metisse certainly didn’t hurt either!
Von Dutch’s artwork, a usual, is Krazy! Check out the full-sized Harley chopper he painted on the barn!
Directed by Bruce Kessler, former race car driver at Le Mans, and team driver for Lance Reventlow’s Scarabs, consultation from Sonny Barger
See more here:
The most obscure Von Dutch piecea of art, the credits for the movie Angel From Hell, and the murals in the bars, and the garage ( I now consider this the most thorough Von Dutch blog on the internet)