I've got a 105 X5 that I installed this spring. I've been pleased with it so far, save for one annoyance. The arrow on top of the head makes noise when it turns, particularly in the morning when it's damp. Would just spraying some WD-40 around it take care of it / be safe? The safety thing is my biggest concern - it's obviously sealed up and waterproof so I'm 99% sure it'd be fine, but just want to make sure.