Be careful how you do it though. When I bought my 240, the rear fog lights were on whenever the headlight switch was in the first or second positions. With the Park lamps on, flipping the fog light switch only served to turn on the headlights. ??? was my reaction. With the headlights on, flipping the switch only managed to turn on the bulb failure sensor light. The only thing I can figure is that sometime in the car's past, the owner had left the switch on with the bulb burned out and went to have the car inspected. (that's one of the silly things we have to do every year here) The inspector probably failed the car due to the uneven lighting at the rear not realizing that it was a rear fog.
This resulted in someone wiring a bulb and socket to the tailight in the passenger side corresponding location and my mysterious lighting problem. It looked as though my brake lights were on all the time it was so bright back there!
While I was at Martens for a club meeting, Rick took a look at it and proceded to yank out all the errant wires, and that fixed the problem.
By the way. As long as were at the back of the car, I should add that I have found it useful to engage the backup lights while moving forward to ward off tailgaters at night. You can do it with manual transmissions, but just be careful you don't get too overzealous about getting that guy off your bumper. The tranny might not be too pleased. I wonder if there's someone who has installed a switch that can be toggled on so as to trigger the lights without taking the car out of gear. It's probably very simple, but I am no electrician.