"CHECK SIDE LIGHT" - A literal Hack!
If you have a later model E39, you might see this alert on the lower middle display, as it did for me. After some walking around the car and the requisite reading online, the problem seemed because of the driver side angel eye (USA, 2003 525i). Generally, I tend to understand, then ignore these lights if warranted. However, the "red corners" on the display - making this a more critical warning, and the pings during every turn on and off, grated on me enough to try to replace the light. Thus started another saga. As always, please treat this as entertainment. And not Dialysis. To paraphrase the legendary Nelson Pass. YMMV and assume your own risks...... One thing about the E39's headlamp is that the bulbs are accessible without removing the wheels or the bumper, unlike the E90 which took me 4 hours to change a similar angel eye bulb. I digress. I yank on what looks like the right part. And it comes out. Or atleast something comes out. 2 out of the 3 parts of this "ass