Thought I would bump this old thread as I have finally sorted the problem and this will hopefully help anyone else with a similar issue.
Turns out it was my neutral deadband setting on the esc.
It's the last thing I would dream of checking but def the problem!
I use a cheap radio (flysky gt3c) and i think its the pots that are the problem.
I found this info from team Novak. According to Novak , dead band can affect steering as well as throttle??!
http://teamnovak.com/tech_info/view_article/35
I had the esc deadband set it to 1% that's when it stared paying up ,but I had no idea because I changed so many other settings on the speedo at the same time. 1% is so sensitive it would make throttle blip just by turning the tx on and off. Also if I span the wheels by hand it would 1/2 throttle for almost a second!
3% is default on the esc and it make the throttle and stearing glitch occasionally during a race day .
Set it today to 5% dead band , all glitching gone! Really good days racing!
So if you have a glitching car and your using a cheepo radio, esc dead band settings maybe worth a check.