Richard, IIRC the Audicator had separate L/R connections to indicators & live trigger from brake switch and neg earth, I'll try and find my old wiring diagram
It sounds like the device you describe would be fine with a 3.7 Roadster Jon. The diode isolation I mentioned appears built-in given the individual trigger connections for left and right. If these and the brake light kill trigger are taken directly from the lamp feeds they would be after the BCU. This and the braking kill function suggest a logic driven device so no extra loading on the lamp circuits either.
