Running Auto Shop from Home/Driveway/residential Area.?

My neighbor is running an auto mechanic shop from his driveway. I live in a city withing the Los Angeles county. The average price for a home in our block is $450K and $500K. I lived in my house for 5 years now, he stared running his business about 3 months ago. At first it was one or two cars he would work on. Now he has a hand full of cars. Last week I counted 11 cars parked on the street waiting to get service. He has batteries, engines, transmissions among other car parts sitting on his lawn and driveway. It makes our block look like an East Los Angeles or Pico Union block. What should I do and to whom should I report him too or should I mind my own business. Its difficult minding my business when the house next to mind looks like an auto shop in El Monte.