Maybe you should visit another VW dealership and take out a different V5 to see how the two compare? Or consider an AA vehicle inspection?
Assuming you're buying the car as an approved used VW you should be confident it's sound, but I know what you mean, when you're spending that kind of money you want to be sure it's A1.
Hope it all works out for you, let us know how you get on.
Stu.