It is a tough one cause of the mk2 but generally cars are a little cheaper in the winter.
I personally think there wont be that much difference in price come the summer. Over the past few years they have kind of flattened off. OK so there are some real cheap ones with high mileage and concourse cond that are 14k plus but generally the average cond and mileage ones wont go up or down considerably by the summer.