Richard's Performance Muffler: RPM in Vista is a shop I've used and recommend. Good work, good price.
Herm the Overdrive Guy: I bought my dual master cylinder upgrade from Herm. He has lots of good stuff for old Jeeps.
Richies Rear End Repair: (760) 724-3769 The 'Auto & Truck Proctologist' is in Vista and lives up to his good reputation. Recommended for all of your axle service needs. He's got a ton of knowledge and experience and best of all he's a Willys buff.
Tow-Rite Towbars: This is a local company making a new type of towbars for Jeeps and other vehicles. If you're looking for a towbar, check them out.
This place a good source for some of those hard to find stock parts for old CJs and Willys:
If you click through to their site from here and actually buy something, I'll get a small commission off it! Come on guys, I need more Willys bucks!
North County Crawlers Jeep Club. Based out of Northern San Diego County.
Early CJ5.com: A friendly group of knowlegable old Jeep lovers. None of the BS or negative smack talk that seems to clog up some of the other forums.
Willys Tech: Not as user friendly as some sites, but there's a lot of good info to be found there.
Old Willys Forum: Just for Willys Wagons and Trucks.
My Jeep Rocks: Good local trails info listed on this site.
Just Runs: A San Diego based "non-club" club. They organize a lot of runs.
SDORC - San Diego Off Road Coalition is a non-profit organization dedicated to the promotion of off-roading as a safe, healthy, family activity. This group does a lot for the off road community. Please support them anyway you can.
American Sand Association (ASA): Some Jeep talk with good info on Glamis and Ocotillo Wells.