There are murals on the 20th Avenue and Solano Way sides of the store at 1200 20th Avenue. The store seems to have changed hands several times, so it's not clear who the mural is advertising for. It reads "Spark Plug Customs" on the 20th Ave side.
Another piece has a picture of the Golden Gate Bridge, the ocean and a cityscape with a lot of sound system logos.
The Solano side has several figures and a piece by Ceaver in his signature reds and yellows. Better picture of the Solano side here. It says "RIP Shrooms." The mural is by CEAVR, WIRE, OYA and LOGO (maybe?)