I would venture to say something is up with the ESC/RX. If you are handy with a multitester you could check voltage to the servo and stuff, but that's a bit more involved.
I would read the manual I linked thru and try rebinding the ESC/RX and see if that does anything, the ESC probably should not be making a clicking noise.
If you do have a local hobby shop, take the battery pack and the car in and see if they can trouble shoot it for you. I think this has been suggested once before.
They (if they are a reputable shop) should be able to tell if the battery pack is good or not, at least.
They may even be friendly enough to help diagnose the car, although I think it's the ESC/RX combo thing that is causing the issue, i was leaning towards the steering servo yesterday, but then again it's hard to diagnose over the internet.
So give the rebind a go and see if that helps.