So a question for those of you that live in the rust belts and harsh winters with salted roads. My Cousin has 2009 Chevy 2500HD LTZ 4x4 diesel. He will be spending 2 winters in Wisconsin (in the Navy and they are building on of the new LCS ships there). He is wondering if/how important is undercoating for protecting his truck. Is it worth it? Easy to do (DIY or pay someone to do it)? Pros, cons etc. Any feedback would be great. Thanks.