right then 13 on or bon or whatever the **** you call yerself. check out reply no7 as this asks about leaky sunroofs so stick that in yer pipe and smoke it
there are recon units around with a warantee if you're brave enuff to fit it yourself. Have a look at one of the uk breakers sites they fire up your details off all over the shop, I had an offer of one from Bristol somewhere £150. Didnt go for it tho... wasnt brave enough.
Did mine in-situ as removing the box looked like far more work than doing the seals, as it was, apart from working upside down I don't think it would have made the job alll that much easier.