[mikethefireman]

In addition to Centerpunch’s solution, it looks like TripleR makes a CAN bus module for triggering add-on lights when the high beams are on:

Lazer CAN Interface (Dual-Output)

The Lazer CAN bus Interface provides an effective solution for detecting both High Beam and Side/Position Light activity, where it is not possible to detect a 12v signal at the back of the standard headlamps. The interface, developed in partnership with UK manufacturer CanM8, can identify both...

www.lazerlamps.com

I've seen this on the Lazer site - almost bought some lazer lighting actually... Interestingly, he refers to "if there's 12V going to the lamp, you don't need it". But then in other sections of the forum they point out that the 12V feed (which I can confirm) doesn't vary as there's no unique HB element, it's just a signal that activates a solenoid to change the lens position. So it sounds like this Canbus module and maybe it's contactless reader might be a winner (I can then disconnect the lot and relocate to another car if desired with out remediating wiring splices...). I'll report back if that's the path I take.

 

[mountaintuna]

Sorry for the late response. I just drilled through the plastic license plate holder and reinforced with washers.

 

[mikethefireman]

In addition to Centerpunch’s solution, it looks like TripleR makes a CAN bus module for triggering add-on lights when the high beams are on:

Lazer CAN Interface (Dual-Output)

The Lazer CAN bus Interface provides an effective solution for detecting both High Beam and Side/Position Light activity, where it is not possible to detect a 12v signal at the back of the standard headlamps. The interface, developed in partnership with UK manufacturer CanM8, can identify both...

www.lazerlamps.com

End result is the CANBUS module (CANM8) but the Lazer sensor is not a bad additional option to avoid physically tapping into the CANBUS wire.