Again- really like the lights~
I have an idea. Since you are already using resistors to vary the current and adjust brightness, why not rigg two seperate circuits to your taillights, one with high resistance an one without, then use your switch design that you use for the high beams to switch from circuit to the other when you step on the brakes. that way you can use your existing lights for both effects, just like a real car.
also, for an electric car you should try pluging the esc into a y-harness and then into the Rx. then try pluging a micro servo into the other part if the y. the servo should operate with the throttle, and you can use microswitches to operate the brakelights on this servo. the servo could be mounted to the body, so the only thing you have to do is turn on the light and plug in the servo.
cant you run all the led's in a system parralell with only one resistor? led's take practicly zero current, so the number in a chain shouldnt matter, plus that should simplify your wiring.
I dont really believe in "trade secrets". most popular products today are bought not because they are secret, but because it is more convienient to buy the product anyway. For Example, there is no secret to growing corn, but you have still probably bought it at the supermarket. If you can't do it cheap enough and it is then worth while for someone to do it themselves, It wont matter.
Anyone seen a 10mm white or blue light? they would make for great foglights.