I would make more if I had the time.
Save some cash and make one, here's what I used and where I got it from.
WLED-CWHP15 (194/168) wedge base bulb from http://www.superbrightleds.com/mini-wedge.html
1158 light bulb base (also at superbrightleds.com)
4 male slide crimp connectors
4 female slide crimp connectors
2 male barrel crimp connectors
2 female barrel crimp connectors
Full wave Bridge Rectifier 4amp 50PIV (Radio Shack part #276-1146)
100uf capacitor (Radio Shack part #272-1016)
14 ga. wire
heat shrink tube
Use the pics above to see how it all goes together. I used a red sharpie to mark the positive and black to mark the negative terminals. The "~" terminals on the rectifier go to male slide connectors that plug into the wires that normally connect to the socket, polarity doesn't matter with those two wires.
The LED bulb is the most expensive part ($17) but everything else is real cheap.