There's been a thread going on BF.c recently talking about how to disable the daytime running lights on the Canadian E34 models - I thought it would be worth cross-posting here for the maX E34'ers.
Basically, E34s used at least two different DRL setups, likely depending on the build date of the car. Don't know for sure when they changed over. Either way, the thread has details about both setups and explanations of the easiest ways of disabling them.
Definitely worth checking out if you want to put an HID kit in your E34!