I didn't know this and want to pass it along to 17 Mirage owners and tire kickers.
Looking on the iihs.org site the 2017 Mirage under the other safety feature section it states Rollover sensor: designed to deploy the side curtain airbags in the event of an impending rollover (beginning with 2017 models)
Also the offset crash has improved to marginal on the 17 models before it was listed as poor in the 14-15 models.