EDIT 1 : YEA!!! My 500th Post!
EDIT 2: For Nox, if any of the info in this post fails, try
www.questformadness.com
Hmm, it doesn't appear that you have a cripple capacitator on your controller, but here's a list of stuff you can try instead

:
1. Undo the antenna knot under the car's PCB.
2. Install
brand *spankin* new batteries in the remote, or do the triple-battery controller mod like hog suggested. Note-I'm not sure how to do this, but I'm sure a l33t electronics d00d like you can pull it off.
3. Install a telescopic antenna from RS on your car's remote.
4. Buy some 22awg or higher solid copper cable from RS, and use a bit for a new antenna for your car.
5. Hold the darn thing over your head?
6. Have I run out of ideas?
Well, if none of these suggestions work, and you're abolutely sure that the cripple cap removal on the car did nothing for range, than I suggest you re-solder in the car's crip cap. It will at least help to block out interference from other Bit frequencies. I say this because after removal of my Hiroto's car crip cap, I noticed my 27mhz controller was able to control the 57mhz car. Alas, it's quirks like those that make these little guys so dang fun!