A friend at work needed to sell her Audi A4 Sline, 4 years old with 66000miles on the clock (2.0 TDi) and webuyanycar offered her under £9000, which was about £2500 under market value of similar models on the interent at the time.
So I offered her £10000 and bought it off her, hehe. I can't resist a bargain (plus needed a diesel)