My dad has a really nice escalade car?

Well the car being an Escalade and all, I'm uming it's on leather? If so then you're not going to be able to use any of the traditional mildew cleaning products out there, as they'll most likely discolor the leather. Your best bet short of simply replacing the seats would be to get a gentle detergent cleaner, such as dawn, and a soft bristled brush and a whole helluva lot of elbow grease and scrub those seats down. After that, towel them off real good and get them in a dry, warm place. Consider a leather conditioner then. Good luck with it.