caravan cleaners

You will probably find that using something like Fenwicks caravan wash followed by their Bobbydazler will do the trick; widely available at caravan dealers.  If the gelcoat has faded a product called Bullet Gel Coat finish restorer will bring the shine back to your caravan.  DO NOT use T Cut or similar on caravan paint as the paint thickness on caravans is less than that on cars and you risk damaging the finish on your caravan.  With Bullet a bit of elbow grease is necessary but it is worth it.