The battery is like this because:
1- I just like it
2- Balance. I have a lot more weight on the rear left than on the front left so it makes sense to place the battery like this. Not a single extra weight was added and the car is 100% balanced. Weights 1415gr (ready to race).
3- Drivetrain. I've flipped it so I can push the motor as much as possible to the middle of the chassis. This way I don't need to add extra weight or to move the lipo further out. With the drivetrain like this I can't fit the lipo on its place as it touch the front belt.
4- Battery connection. This is a side effect. If the lipo was in its original place it would be difficult to plug in the connector due to the bulkhead/top deck. It would required a L shape plug/wire.