BMW is actively researching the use of augmented reality for servicing cars:
Augmented reality (AR) has been getting a lot of press for recent advancements on the iPhone and Android platforms. While it's nice to see these developments, thus far I've thought the excitement is a bit premature. It's as if we all know how amazing a truly integrated AR system would be, and have projected our future excitement onto these nascent attempts. That's not to disparage those efforts, but so far they amount to little more than live updates of Google Maps' Street View - nice, but not revolutionary.
One of the problems is that the current crop of AR applications are merely location-aware; they overlay what are effectively landmarks on any given point of view. True augmented reality will have some level of understanding and interaction - as demonstrated most basically in the BMW video. The next step for location-aware applications will be to paint virtual arrows on the ground to demonstrate where to go to get to a destination; not merely highlight the endpoint.
Car companies should be all over this; the need for rapid information visually connected to a potentially unfamiliar setting is imperative when driving. The basic HUDs that have been implemented don't quite get the job done.
One of the difficulties, however, is the method of display- it is commonly believed that AR information can be projected on a car's windshield, but that overlay would only be calibrated for one person (in other words, it would distract and confuse someone in the passenger seat). Another common solution is to turn the windshield into an opaque display, which shows an annotated video feed, but this removes all depth perception - a critical piece of spatial information. Ultimately, I believe some of the ongoing research in 3D televisions will come to bear in this environment.
Until then, lucky iPhone 3GS owners can get their AR kicks from Yelp...