This is a construction to make an extra brake light to my Saab 96. As the car is old (and beautiful :) ) a normal extra brake light won't fit. Instead I use small 3mm led's mounted in the window frame. Here is the schematic:
Five Led's in serie gives a voltage drop of 10.5 volt which keeps the voltage drop in the resistors at a minimum. A zener diode and a capacitor protects the diodes.
The schematics has been redrawn, the zener and capacitor is gone. The leds are now connected in two serial groups in parallell connection via two parallell 150ohm resistors.
And it's mounted in the car! See pictures below: