I'd like to wire the fog lights to function with my high beams. Can I achieve this goal without giving my 2008 xk kitty kat something else to complain about?
wj

 

Probably illegal IF you have state inspection

 

Texas doesn't. Would only use out in the middle of nowhere, no lighting, only the dark sky and wild animals bounding about!
wj

 

There are all kinds of relays available for the situation you wish. But your question is to the root of the matter; "...something else to complain about?"
I, on the other hand, spent some time investigating auxiliary ralley lights for my car. (I enjoy driving winding roads at night). The trouble is, I couldn't figure out how to place them, aesthetically, on the car. I was looking at a number of options in the Bosch Pilot series.
Let us know how it works out for you.

 

I dunno if it can be done but it seems like a risk. The lighting goes through the auxiliary switch pack which is small and located behind the dash under the left vent. Switch 1 and 2 are involved but I can't tell from the wiring diagrams how it interacts with the high beams. also the high beam flash disables them. This is apparently US and Canadian markets only, perhaps Euro cars don't have the same restriction as there's no mention of that in the manual. So my random thought is to look in the CCF and see if there are other options to select, because there's a lot of things running through that little switch pack.

 

I was concerned @ feedback into the electronic controls. I guess the safest is the crudest!
Use the high beam + to fire a relay that feeds 12 v to the fog lights and also breaks the factory feed, a second one ( also fed by the high beam +) to supply a ground path and break the factory path back to the switch pack. Since I have the Cambrio Temp Gauge set up I can probably add a switch and led to it that controls when it is active.
Just thinking...installing the passenger leather is first on my list.
wj