See also:

Additional safety precautions
• Never let passengers ride in the cargo area or on top of a foldeddown back seat. All occupants should sit upright, fully back in their seats with their seat belts on and their feet on the floor. ...

Spark plugs
Make sure to install new spark plugs of the correct heat range. ...

Hybrid-ness
Before I get into the performance and technology aspects of what makes the Sonata Hybrid tick, I've got to point out the fact that the Sonata Hybrid looks dramatically different from its gasoline- ...