Another update, as you probably noticed went with the glass from the GL tailgate, ummed and arred for ages because I wanted the oe look but I just didn't like it, so no spoiler;
Also got a top tinted front screen as it was only a few quid extra, so I thought why not;
Then got the xenons wired in as neat as possible, all hidden whilst the bumpers off and got the side markers wired in,not the neatest I must admit but it works;
Tried the US rear bumper on and it fits spot on;
So got it prepped,it was a fully painted bumper but the top had been painted black at some point and it'd had a crap