To be honest the dealer we took it to didn't seem overly interested in the problem.
They are local to work so it seemed the perfect solution, and with a little persuasion we got a courtesy car too. They had my car all day so you'd think the problem would have been atleast discovered if not resolved. But no, on pickup I was told that they couldn't "put their finger on the cause of the noise" and "it could take hours to find the cause". It was suggested I went away and let the noise "get worse" and then take it back.
So for simplicity and a no nonsense approach we hoped to take it to our very friendly and efficient local garage but from what you guys have all said this is not an option. Shame. Hey ho. So I'll be trying some of the above tactics with Seat in Stockport I think!!