Try taking it into Halfords, yes you have to buy the bulbs from them (which cost more than a lot of places) BUT they fit/replace bulbs for just £5-£7 depending which bulbs they are, so it saves you the mega rip off of the main dealers.
I had my side and head lights replaced at halfords, cost me a total of £32 including fitting, BUT vauxhall wanted a choke worthy £159 and that did not include the price of the two bulbs!
Fiona, December 2010