The fog light mod is a common mod, I did it on my 87 Starion. They won't come on without the driving lights, but don't require the headlights to be on anymore when the mod is done. This is basically a one-wire mod, you tap into one of the side marker 12V wires. Check out this post from starquestclub.com, your best Starion resource for this stuff...
http://www.starquestclub.com/forum/index.php?showtopic=28057