Here's where I have had success getting parts and hopups for my Xray. The car is new for me and I've already gotten most all of the hopups available for the car from 2 different hobby shops. The first is Atomic Hobbies in Florida.
www.atomichobbies.com and the second is Rider's Hobbies in VA. They don't have a site but their number is 703-430-2202. Both of these places I just called up and they were helpful. Rider's has virtually every available part and optional part for the car in stock. Talk to a guy named buster and he will help you out.
Although this car doesn't need much for hopups but its so pretty, you just got to add some of them...hehe