3rd brake light wiring

[noseoil]

This was my thought originally, but if a turn signal is on, without the brake pedal being pressed, then one side will supply a "blinker" signal to the 3rd brake light. If the brake pedal was pushed while a turn signal was on, it would work, but I'm thinking I should just buy the over-the-counter one. I'm not sure this is a legal configuration to use on the roads (blinking 3rd brake light & turn signal at the same time) as if there's a collision, it could lead to legal questions in today's world of personal injury & accidents.

[kludge]

http://www.sentex.ca/~mec1995/circ/3brake.htm