A battery mounted across the chassis will not make for very good polar movement..I understand there's not much room in the chassis, but it's always good to have the weight towards the center of the car.
mafia - If the car turns out to be pretty good, I'm sure there will be enough different to offer a completely new kit. At the very least, the rear end will need a ton of new parts and if the car is going to need a LOT to convert an older kit, I'm sure it would be more economical for the company and the consumer to have a completely different kit.