A Flat Tire
If you've got a spare in decent condition, this is usually the fastest fix on the list. We get it mounted and you're back on the road.
If the spare's flat too, missing, or the vehicle doesn't have a full-size one (common on newer cars, which sometimes ship without a spare at all), the conversation shifts to getting the vehicle to a tire shop instead. We'll tell you honestly which situation you're in rather than pretend a bad spare is a solution.