undercoat

do you northerners with an rsx protect the underside any specific way? or do you just leave it alone? as far as i know, salt will be used on the roads along with chemicals and i'd like to know if something should be done to the car. anyone with a high mileage rsx used during brutal winters...

Does anyone know a good product that will product to protect the underside of the car during the winter? A friend at work says he sues this stuff called "Undercoat". It's a tar-like stuff you spay on the bottom of the car. Any one heard about this stuff? Also, what do you think is worse...