What about respraying the roof your self. Give it a light sanding over , mask it off by rolling the masking tape over it self so you won't end up with a hard edge on the paint. I would personally respray it black. It may not look perfect but it will certainly look better than what it is now. If it all goes horrible wrong you could resort to a vinyl wrap. Just make sure all the old polish has been removed otherwise the new paint will react with it causing what they call " fish eyes ". Give it a go, you've got nothing to lose apart from a few hours of work and a few £s on paint , primer..