Going down Main St in El Cajon, you are immediately struck by the number of businesses labeled in Arabic. Lots of Chaldean Christian businesses in the area. A much smaller number of muslims. The muslims hang out closer to the mosque near Balboa Ave and I-805. Most shop at the Target near Balboa and Genessee. I lived in the Clairemont area from June 2011 to Sept 2014.
We spend a lot of time each summer in Coronado. Over the last couple summers there has been a huge increase in the number of Muslims visiting Coronado - especially on the weekends. They walk in big groups along the Ferry Landing and make it very hard for you to walk around them. They never move as someone normally would to let someone pass by. It gets a little scary sometimes. I guess I am paranoid but I always feel they visit Coronado to spy on the Navy. Just hope someone is keeping an eye on them.