To be honest, if I was going to buy a car at the far end of the country , regardless of being a reputed dealer, I would have had an independent inspection done. The car is 7 years old, so not that young. As for the faults, I am sure he would be just wanting to punt this back out asap, as was only a trade in. I can understand your frustration with it, but I was always told to try every switch and button when checking a second hand car, which I did when my mate bought a 2008 TT last week. See if he comes back to you , but we haven't used tax discs for over a year now, so as for a windscreen, you may need to claim on your insurance as damaged and see if he might pay the excess, as it wont affect your no claims.