Picking up my new car soon. A few questions.

You'd get a pro-rata refund yes but they normally add a penalty of a month or so I think. But as you say they're not obliged to give you that years no claims so if that's important to you then I'd take their quote. It's a maths question really. i.e. will the extra you may have to pay out to finish that year work out to a lot more than the months of no claims you would be throwing away? If they gave you a good enough quote in the first place they may give you a good quote now!

You could always get quotes from elsewhere first and use them as leverage.

There are some very good threads in the detailing forum and even a dedicated thread for dark pearlescent cars:

http://www.audi-sport.net/vb/forumdisplay.php?f=116

For oil just go to Halfords mate. They have those books that tell you which you can choose from and then it's up to you which brand to pick.