Mazda 6 Service Manual: No.7 slow return to idle

No.6 cranks normally but will not start

No.8 engine runs rough/rolling idle

Other materials:

Mazda 6 Service Manual: Plastic Part Maintenance
When cleaning the plastic lenses of the lights, do not use gasoline, kerosene, rectified spirit, paint, thinner, highly acidic detergents, or strongly alkaline detergents. Otherwise, these chemical agents can discolor or damage the surfaces resulting in a significant loss in functionalit ...

Mazda 6 Service Manual: Headlights
Turn the headlight switch to turn the headlights and other exterior lights on or off. When the lights are turned on, the lights-on indicator light in the instrument cluster turns on. NOTE If the light switch is left on, the lights will automatically switch off approximately 30 seconds ...