Safety Related X5 Options

• Xenon headlights ($500 MSRP for the X5) evidently are much more effective at lighting up dark roads and thus important for visibility.
• Park Distance Control ($350) lets you know how close objects are behind you, even if they are below the line of sight out of the back window. One X5 owner said this system alerted him when a little girl ran behind his car as he was backing up and he wouldn't have stopped were it not for the PDC beeps. Obviously the same thing applies to dogs, etc. as well. As a bonus, this makes parallel parking easier without bumping bumpers.
• Sport suspension improves handling ability, which can be important in emergency situations. Note that tires do not all work equally well in all conditions. The 19" performance tires that used to come on the 4.4 with sport, but are now an option are a safety hazard in snow, ice, and even just cold weather. I'm not sure how well they do in rain or how well the 18" tires do in snow, but both the 17" and 18" are all-season tires and should be okay in most conditions (the 17" tires may be slightly better in snow).
• Self dimming rearview and external mirrors ($300) can help prevent being blinded by headlights behind you. On a sedan, this would be a very useful feature to help when higher vehicles come up behind, but it's unclear to me how important this is on a vehicle that is already a bit higher than sedans. Still, could be useful when the really big SUVs/pickups get behind you. Reports suggest that it dims so much that it can be hard to see what's behind you, but since it is based on a simple light sensor on the internal rearview mirror, it should be possible to (a) turn it off completely by covering up this sensor with something opaque, or (b) decreasing the amount of dimming by covering the sensor with something that lets only a portion of the light through.
• The multi-information display with onboard computer (upgraded computer) option ($300) includes an adjustable speed limit warning that will warn you when you exceed the speed you have set. Since the X5 feels so quiet at high speeds, this could help avoid accidentally going too fast. This has a number of other convenience benefits, including an automatic ventilation system that can be programmed to vent outside air into the car at a preset time. Very handy on hot days parked in the sun. It's unclear to me whether this option is available for the 3.0i as a standalone option, or just for the 4.4i. It is definitely included as part of the NAV option for either trim level (see below for more on the NAV option).
• The BMW Mayay cellular phone ($1990 for NAV system + cost for dealer installed Mayday phone option + ongoing cost for service) is a system like the heavily advertised OnStar system. It requires the Navigation system, which includes a GPS unit (and also the upgraded computer mentioned above). The Mayday system automatically alerts BMW roadside assistance in the event of airbag deployment, providing the exact vehicle position so that they can alert emergency authorities (faster than anyone at the scene probably could). Saving a few minutes in alerting emergency medical assistance after an accident can significantly increase the chance of survival for anyone severely injured. The Mayday system can also help get back stolen vehicles more easily. It's unclear whether the Mayday system is available for the X5. Autosite lists it as a dealer installed option, which may mean that price and availability vary by dealer. Edmunds doesn't list it for the X5 at all. Even without the Mayday system or BMW phone, the NAV system itself might be useful in this regard in conjunction with another phone as you can read the coordinates off of the NAV system if you don't know where you are in terms of roads, intersections, and highway exits.

Other health and safety related consumer info that I've collected.