If you need, i have a couple hundred high quality 10mm LEDs and resistors to go with them... I have clearly evolved past the simple home made light and no longer require them. Hit me up, all colors, cheap.
I was just going to start a new thread on this, but seeing this is here, I'll just add on.
This is a self-made dashlight I just finished, I've been working on it for several months. It originally started when I saw a computer screen cleaning kit in a shop. It came in a transparent blue box that was just screaming to be made into a dashlight.
This is 18 4-chip 10mm LEDs on the circuit board. Each LED is roughly the equivalent of four regular 5mm Gen I LEDs.
Inside is a flasher from board member Changchungleds. As of now, there is no flashback shield or mounting bracket - though it probably could just be Velcroed to the dash. I probably won't be using this, but it was a fun project.
Intensity-wise, I'd say that it is a little bit brighter than a Hawk-I.