The Toyota GR86 has a standard driver’s side knee airbag mounted low on the dashboard. The knee airbag helps prevent the driver from sliding under the seatbelts or the main frontal airbag; this keeps the driver better positioned during a collision for maximum protection. A knee airbag also helps keep the legs from striking the dashboard, preventing knee and leg injuries in the case of a serious frontal collision. The MX-5 Miata doesn’t offer knee airbags.
Over 200 people are killed each year when backed over by motor vehicles. The GR86 Auto has standard Reverse Automatic Braking that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The MX-5 Miata doesn’t offer backup collision prevention brakes.
The GR86’s driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The MX-5 Miata doesn’t offer a driver alert monitor.
Both the GR86 and the MX-5 Miata have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, lane departure warning systems, rearview cameras, available blind spot warning systems, rear parking sensors and rear cross-path warning.

