Dont you watch mith busters? They proved that a dimpled "golf ball like" surface on a vehicle improves fuel mileage. You just gained free gas mileage while towing!
All joking aside, I got nothing on the fiberglass sheeting. First thoughts would be its a heavy material and would fade quickly in a few years sitting outside. Ive seen some red fiberglass trailers that looked pink after about 5 years. Eric