Don't think I've ever heard of the glass cracking on a Sky View. probably because it doesn't get hit by stones and it seems very solid. If you have comprehensive insurance the sky view would be covered with a small excess anyway.
I'm thinking about selling my 2007 2.2 JTS, it's only done 29000 miles. I just started a new thread called Brera 2.2 Price if you want to look.
Issues to look out for:
Should have green power steering fluid, not red (which they installed in some cars from factory and can cause steering rack to fail, particularly in the heavier cars)
Rocking drivers seat (2006 models mostly)
Squeaky seat belt buckles (again 2006 mostly, after this they put fabric squares on the buckles which prevent the squeaking against the leather seats)
A few cars have had stretchy timing chains but this would be obvious as you get warnings coming on the dash (P0016 error) even before the chain goes properly wrong, and car would have sluggish power delivery. I doubt anyone would even try to sell a car that has that issue as you're going to notice the warnings on the dashboard ("Get Engine Checked") every time they put the key in. So look at the dashboard when they put the key in and start the car!!
Not much else on the petrols, which are fairly bulletproof, but diesels tend to have issues with clogging DPFs and EGRs, especially if town driving or if remapped. That can be solved by removing the DPF and EGR and adjusting the ECU software, but that costs about £700, so if you want the diesel make sure you buy one that's already had the work done, and that the seller supplies the DPF to swap back in at MOT time.
Brat Pack no.8