I had a friend who had a cart with his brother but they gave it up in the mid 2000s. As I remember, they had to have a permit from the County of San Diego Health Department and a business license with the City of San Diego. I think the deal breaker was when the Health Department changed the regulations to where the hot dogs couldn't be in an ice chest, they had to be refrigerated. I do know that when they were in their heyday, it came down to location, location, location as to whether they made any money or not.
The stickers on the upper right hand side are business license and health dept inspection IIRC.
Here they are at a BMW event I was co-hosting back around 2005-ish.
