I had mine done by Kustomworx (RIP) in sandy (beds). Cost me about £250, but they did a pukka job., Only slight problem is that the bootlid wouldn't shut easily due to the plastic trim on the underside of the tailgate. I had a play with it and found all you have to do is remove the screw that is in the handle area. Calibre coachworks are in the bedfordshire area. 01525 403050.
www.calibrecoachworks.com Or check out April 2004 Max power. They did the cover astra!