I see this is many years old and recently brought to the top.
If you really want to protect your headlights, I suggest adding some headlight protection in the form of clear plastic. Many are familiar with the "clear bra" paint protection kits available for the areas of our cars that suffer from chips. They have thicker plastic for headlights foglights. http://www.xpel.com/products/headlight_protection.asp is one example and what I put on my 2001 530i back in 2001. I guess I should try and post some pics of what they look like today.
2001 530i/5 (E39), Topaz Blue/Stone Green/Black (97k miles)
2005 545i/SMG (E60), ED Order, Titanium Grey/Grey (lease transferred...no longer have)