I think if mine began to puff then that would be that, would be a case of new LiPo's as I don't think there would be any more room. Before getting the car and trying for myself, these are the cells I would have brought had mine not fit:
http://www.jespares.com/electric-mod...tegory_id=1168
According to the BRCA list, these are pretty thin and space shouldn't be an issue! You may wish to double check though!
Other than that, I was considering an Xcelorin Shorty LiPo but the only downside was the capacity, I wasn't sure if they would last. They would fit under the belts and I could have manoeuvred them away from the area around the front belt where I was having trouble.
Alex