http://www.dsgauto.com/ are very competitive.
Consider VERY carefully if its the right thing to do though, don't be seduced by the affordable monthly payments.
Say you take out a 3 year lease @ £300 a month. Thats great, you can afford £300 a month, and you get a nice new car for that. But consider it from this point if view..
You are, effectivly, renting the car. It isn't yours and you don't own it. That £300 a month is £10,800 over 36 months. So you pay 10 grand to own a car for 3 years and after those 3 years you have nothing to show for your money, the car goes back.
Instead, considering buying a car outright using a personal loan - avoid brand spanking new stuff and you'll be unlucky to find something that will depreciate by £10,800 over 3 years and at the end of your payments you are left with.. a car that YOU own