<---Pretty much agrees with Hohwart on most things in this thread.
Here's my thoughts on why spec cars almost never work... In a nutshell, 95% of the hobby is the stuff you do at home. You got into the RC car "thing" because you wanted a hobby, something to fill your time.
When you have a car with only 15 parts on it, all of which you can't work on, and you cannot make or buy pieces to improve it,
what exactly are you supposed to do with your spare time? I suppose get another hobby, Golf, Motocross, hit the dunes, PS3, etc.
Most spec cars eliminate the hobby, from the hobby.