I would like to make one.
Everything you need you should be able to find at your local hardware store. You'll need a roll up window blind end bracket
<CLICK> , a small flat reinforcement bracket
<CLICK> , a thumb screw, two nuts same thread as the thumb screw, a 6 or 12 volt (depending on your application) LED and a dab of epoxy or JB Weld.
First drill out the center of the roll up blind bracket to accept the LED. Second bend the flat bracket into a "U" shape. Third sharpen the end of the thumb screw to a point. Bond the two brackets as shown using the epoxy or JB Weld. Bond one of the nuts to the bracket as shown. Attach the LED and solder the ground wire to the "U" shape bracket. Screw the second nut onto the thumb screw (used as a jamb nut if necessary, if not necessary you can discard it). Extend the LED hot wire with a light grade wire (I used speaker wire) to reach the high beam side of the dimmer switch. Assemble as shown, attach to your lower dash lip and enjoy.