What are the symptoms that my engine oil is too thin?

I recently visited my local used car dealership, and I saw a 2014 Dodge Challenger Shaker. I know they’re relatively rare, but I’m wondering how rare. Do you know how many 2014 Dodge Challenger Shakers were made?

I’ve been a Mazda owner for years, but I’ve only recently gotten interested in the underpinnings of the vehicle. My car has great acceleration, and it’s just as good as any American car I’ve driven. So where does Mazda make its engines?

A couple of weeks ago, my dad borrowed my car and needed to turn off the passenger airbag. I forgot that he had turned it off until we spoke on the phone this morning. I didn't want to tell him I forgot so I didn’t ask him how to do it. How can I turn the passenger airbag back on in my Toyota Camry?