I'm in a similar situation mate and the general consensus is any warranty company will try to wriggle out of making payments. I haven't heard anything good about any of the 3rd party warranties available, but saying that, my Passat came with a warranty when I bought it and it they paid out for a couple of repairs
That was AutoProtect for info. The garage I bought the car from dealt with them for me, I never did. I wonder if that's the key with these 3rd party warranties, let your garage deal with it all?
Good luck anyway, let us know if you have any luck.