Neighbours of ours got their 17 yo son a 'pay as you go' policy on the mother's Focus.
I don't know all the details but you nominate when you need the cover to let him learn on the road and they cover that time.
No night driving to begin with, no mates on board and a few other things like that.
You take 3 months or whatever up front and specify the days/weeks etc., etc.
Worth a look...... Aberdeen is in the cheapest area for car ins though
If you want and can't find details let me know and I'll ask them for more info
Stew,