How do I prevent rodents from motor home during winter storage?

I can tell you from experience that this is a tough one. Here is a summery of what we have done. My brother in law and I went through the motor home looking for places that they could enter. I got under the unit and he was inside with a flash light. Whenever I saw his light we would stuff the hole with steelwool. Later he reenforced the areas with expanding foam. He removed all food sources that he could identify such as boxed or paper packaged foods. He also removed any nesting type material that he could find. He cleaned the area around the outside of the motor home as far out as he could. It is too early to tell if this is working but so far he has no evidence of rodents. Last year, without doing anything he ended up with quiet a problem including a nest in the driver's seat. Not pleasent.How do I prevent rodents from motor home during winter storage?
Shrinkwarp, like they use on boats. And moth balls. They hate the smell.How do I prevent rodents from motor home during winter storage?
get a box of snailbait,wrap exlax around them and lay them all over the place