when I test drove my first scooby (a 99 T reg) the bottom foglamps illuminated with the main beam, which made me beleive that they had a twin filament bulb.

I'm assuming this is wrong and that the fog lamps are only foglamps and dont do anything else - am I right?

 

You are correct, UNLESS:
1. the previous owner uprated 'em to driving lights....lucky you!
Check by looking at the lenses: driving lights will be marked PIAA, Cibie, or Hella. Fogs are marked Subaru.
2. the previous owner fitted a relay etc to make the fogs come on with the headlight mainbeam....pretty useless really, as they only illuminate about 20 feet in front of the car:
Alcazar

 

wasnt the car i bought, but option 2 is what was done to it by the sounds of it.

had to check, changed by bulbs last week and thought I'd done something...