[MetalMan]

1. Can you elaborate on this "bottom plate thingy"?

2. Pull the diff apart, and remove any shims already in it. If you've done that already, you may need to grind that circular raised section on the inner part of the Kyosho spur gear. Looking at the stock steel spur you'll notice that raised section isn't on there.

3. Good choice on electronics!

4. That's going to be a pain mounting 4s2p A123... I can imagine the left-right balance might be thrown off because of the weight.

5. Acrylic might not work so well, because it shatters easily. Thin-walled aluminum should work well and not weigh too much (check out BrianG's Hyper 8 to see the battery tray design he uses).

6. Usually that screw is a 2.5 or 2.6mm thread, and about 8mm long.

7. Gotta love that.