Was driving on the expressway on a day it was raining heavily and water was ponding on the roadway here and there. I was driving approximately 45MPH and would drive through the ponding water, you know the kind you hear washing against the wheel well and undercarriage when you drive through one of them. Keep in mind this was just ponding puddles, not road flooding. After I drove through one of the heavier puddles I heard something scrapping under the the car and pulled over to find that the right side large plastic undercarriage protector had dislodged and was hanging down. It was damaged from dislodging and scrapping along the road so it needed to be replaced. This big piece of plastic was only held in place with plastic trim buttons and failed because it couldn't take the repeated water thrashing. The service writer tried to charge me $260 to replace the part but I complained to the service manager and said that was unacceptable because a part of the car should not come off due to driving in heavy rain at highway speeds through road ponding. He agreed and ended up warrantying the parts and labor.