[BAracer]

Or how about one of these from Truspeed...

   

3.5mm Stereo Jack Plug for Scalextric and Ninco analogue racing.
 
Instead of the awkward and difficult solder connections inside the usual 3.5mm jack plugs, this convenient screw connection system makes it easy to fit the plug to your controller. 

• Wiring
  

• L   Brake                                Green/Yellow       (Red)
  
• R   Output to the track             Blue                    (Black)
  
• Earth   Power                          Brown                (White)