Well I guess it's about time I post this. If you read my "truth about caps" in electronics you will know that I stated the only way for a cap to increase performance is for one to be hooked up directly to the batteries.
This mod is quite simple if you have decent soldering skills.
Simply buy a cap (the bigger the better) from rs (like 2 bucks) and solder the positive lead to the red battery connection at the board and the negative to the black battery connection at the board. The end result should look like this..
What you will notice is an increase in acceleration off of the line and increased acceleration after coasting or braking. This will in NO WAY increase your top speed...