I gave my Swift Suntour, (52 plate on a Ducato Chassis) a wash & polish yesterday, using Autoglym Polish & noticed 'Blotches' on the panels. The cab came up Loverly, but Autoglym doesn't seem to do the job on the back end. Can anyone recommend a Good Long Lasting Polish suitable for the body. I think they are GRP Fibreglass, in reasonable condition. I just want to protect it before it starts to look too 'Manky'. Thanks in advance for any advice.