In the past twenty years hundreds of infants and young children have died after being left in vehicles, usually by accident. When turning the vehicle off, drivers of the Rio S with its optional rear seat reminder are reminded to check the back seat if they opened the rear door before starting out. The Mazda 3 doesn’t offer a back seat reminder.
Both the Rio and the Mazda 3 have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front seatbelt pretensioners, front wheel drive, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, rearview cameras, available crash mitigating brakes, lane departure warning systems and driver alert monitors.

