i'm a valeter and later this week am applying a new product for a caravan dealer called supagard, you may have heard of supagard for cars ( recommended by 22 car manufacturers), but this is a brand new product for the caravan market, it protects your paintwork by coating it in a high tech microfilm that bonds to your paintwork and repells uv rays aswell as preventing the accumilation of grime. Also theres a interiorgard which is similar to scotchguard, prevents spills from penetrating into the fabric and staining,spills just wipe off with a damp cloth. It also comes with a 3 year guarantee. you can't buy it in the shops as it needs to be applied proffesionally, if anyones interested i'll send you a info pack and price list