Yea, packaging is interesting. There are definitely big dynamic performance benefits by carefully working this part out.
On mine, I'm using the back seat area; trying to place the cells as low and centered as possible. So far it looks like I will be able to get a 55%rear-45%front weight distribution with a much lower moment than the original car.
I will be able to orient the motor facing forward in the rear by building a new suspension subframe. If I do it right, I might be able to get rid of some built-in understeer. In the front, it will have to be oriented forward to clear the steering rack.
The cell I was looking at was the Enerdel "moxie" cell:
http://www.enerdel.com/specsheets/en...ell__Final.pdf
What are your plans for linking the cells?