One of the biggest in SoCal was the Yeakel Plymouth Center - I believe it was in the Downey area.
The Yeakel brothers sponsored a lot of local race cars. Top Fuel, Land Speed Record, etc. Check out the following link for a little history http://cacklefest.com/Yeakel.shtml
It would be neat if you could also come up with a vintage set of license plate frames for your car as well with the same dealer name.