Well, Meghan's Uncle's own
Gail's Speedometer in Costa Mesa, but they aren't open Saturdays.
Any weekday I could call and ask them if they would take a look for you. If you want you can give me a list of the things you want checked and I'm sure they'd be pretty reasonable.
Regardless though, if you do need something done and don't mind the mini marathon drive from Chino, you could always bring it to them and get good work done.
However it ends up good luck.