If you fancy buying online you could try
www.jamjar.com. They are owned by Royal Bank of Scotland/Direct Line insurance and are reliable. You tell them what you want, down to the colour. They scour the country and deliver it to your house. If you aren't happy with it within 7 days they will take it away and refund. Comes with the usual guarantees. I would be tempted to stick to dealers as there can be some good bargains. Much more so than before the prices came crashing down....