Rhino Lined truck.

[Ziegelsteinfaust]

I was reading the news before I did my chores outside this morning, and there was a story of how Rhino lining in OC had expanded to do the whole outside of trucks. I have always thought the whole idea was pretty neat, probably real nice for people who really go off road, and it looks pretty cool too.

How does rhino lining the whole truck effect mpg? Since it is rather bumpy by nature of application, and it is the desired effect for bed liners. Does it effect airflow over the truck or car enough to reduce mpg.