The 2012 Mazda MX-5 hasn't been crash-tested by either the NHTSA (National Highway Traffic Safety Administration) or the IIHS (Insurance Institute for Highway Safety). Its small size, light weight, and open-top construction might cause some concern, but its balanced handling, rigid construction, and excellent braking can help avoid accidents in the first place.
The MX-5 comes with anti-lock brakes and front and seat-mounted side airbags, and for 2012 adds standard stability or traction control on base models.
The roll hoops aren't just plastic window dressing, but functional guards in the event of a rollover. They aren't especially high, however.
The lack of official crash test results and high-tech safety features may be worrisome, but the 2012 MX-5's maneuverability may help it avoid some accidents.
Given the relative size of the MX-5 to many other vehicles on the road, even with all of the optional safety features, MX-5 owners will do well to use the vehicle's accident-avoidance capabilities whenever possible.