i put the receiver in the front because for some reason having all the electronics clustered together i was getting interference when the car was 30 feet away, well maybe a stale pack would help out.
or you can get two 2100 30c 11.1v 1/18 scale lipo and run them in series so it would be 4200 being a good bit smaller you could put the in smaller places like one on the other of the servo and one where you have the lipo now
im having just the opposite problem with this 1/8 scale i have to much room it was cheap to only 189.00 for the rolling kit