If you have a GSA, the OEM spots "Aux Headlights" are individually fused.
Main beam is weak especially if you have a half decent LED or HID in dip beam. I wired the narrow angle spots via a relay to work only with main beam. Their power comes from one of the OEM spotlight fuses. I used to other fuse to run the LED daylights.
Alternatively, the under seat power outlet +ve can trigger a relay controlling a septa fusebox. It's canbus controlled so goes off (eventually) when you switch off ignition.