Incidentally, the below is the rear lamp PCB (brake and rear) for an executive car. It has 4.95W worth of led power...and 4.29W of losses in the linear regulators when car battery is 14V.......if you ask me, 4.29W of losses is too much, do you agree?
The rear/brake is the bottom circuit on the page...I did two pics as it was on A3 and I couldn't fit it all on one pic. (as you see, its 12 strings of 3-red-leds-in-series with 55mA in each string)
Also, shown is the whole circuit together, ..'stitched' together "rearlamp total"