Well, just another reason ROAR needs to enforce LiPO's better. So that Manufactures can build the car properly around the battery. A 3mm tolerance is big when compared to the NiMH standards.
ROAR has LiPO Height: 25.1mm +0mm/-3.0mm
I think in reality the measurements need to be more strict and the same as NiMH. 23mm Max /21.5min. Excluding "Bumps" I have a few LiPO's and I enjoy using them, but I don't enojoy having to cut and chop on my car to fit a big capactiy pack in there. Why?, because the other racers have big capcity packs and in stock, voltage is king, and capacity keeps the voltage higher longer. One way to solve that problem would be to enoforce a more strict max height.
The other way to help stock racers is to Limit Capacity. I think a max 3200mah would be a good start for Stock and SuperStock classes.