After driving for 40 years and never encountering this problem, it never occurred to me that leaves and other materials would get into the engine through the grill at the top of engine hood. What a stupid design. The check engine light came on and the engine was running rough, while I was traveling. When I took it in to the dealer, they showed me how there was lots of debris in the engine and which had allowed water to drip in from rain and the coil was all rusty and wet. They said I would have to pay to replace (and of course they would have to order the part) as this was my responsibility, according to them and not covered by warranty.. But how can you anticipate something like this happening, especially when this has never happened with any other vehicle I have had. They ended up drying out the coil and everything has been fine since. So be aware and don't let this happen to you.