The track I go to in Sun Valley has a shop onsite and they carry all sort of 1/5 scale parts for FG, Ladenbacker, Harm and Technokit.
http://www.kzspeedway.com/racepage.htm They maybe able to refer to you their distributor here in Ca.
Have you ever seen any of the cars in person? I saw the 1/5 scale TKT 99E fully hopped up, what a beautiful car. I know FG is more respected but the machined parts on this car are amazing, smooth round edges on all the arms, like a piece of art. There is a car there for sale right now, fully loaded with radio, race ready for $1500!
Also there is a hobby shop on the east coast called Brooklynn hobbies that is a rep for Technokit 718.951.2500