Thank Ray for the tips.
I don't run TAC, but I can't file off the batts compartment too, that because my LiPo is super long, my bad of mistaken 172mm to 142mm of the font size from the net. So, I have to mount them on the top deck. Looks silly but funny, when someone tried to help me pick-up my rolled car and shouted, "bro, you're battery missing!" ... "yah, my car run off solar!". And, I have 2 of those, can't use it on any of my tourers. Then ordered 2 more LiPo, correct length, but thickness, cant fit my 415, it is 22mm whereas TRF have space upto 17mm. But still can use it on my Cyclone, MR4TC, TA05, F103, no big issue. So the long ones, got to stay with M03. I can run 2 nites or 1 weekend day session on just one 5000mah pack, with stops to cool the motor but I notice my ESC is much cooler on LiPo than NiMh, not sure if it is psychological, could be that I added a capacitor with matching NOS labels.
So, die-die I have to solve this traction roll issue, very paiseh already keep screaming "watch car after the straight", "car on ... dunno what turn" and not forgetting those super kind soul who help to give a knock to put my car back on it's wheel.