I would say it's the wrong time of year to sell. I've struggled to sell mine and other than silly offers, no one wanted it. I spoke to 3 dealers, 1 didn't return my call, one said not interested and the other after saying he'd come back to me if interested (at trade price) didn't!!
In the end I have got the deal I wanted for the right car and worked out at £20k for mine (07 plate with just shy of 9K miles)
But.... being realistic they will have had money in the car I bought so who only knows how much I got!!
For interest, I was offered £17.5K, £18.5K and a guy from here turned down my £19.5K for a cheaper Standard GTi.
For all that don't need a car... hold on to it, I would if I could of....... I may buy another some day...