spray.
ebay it.
or go to the auto places. super cheap. repco. or autobarn. i think autobarn has em. cause i havent been able to find any in repco and supercheap.

its just simply applying layers of it to the tail light or headlight with even sprays.
the more layers the darker.
i got mine from the UK for 35 incl postage.
did my eg and still have 1/2 can left.