Thanks guys, that's a very good point - I could make an overpayment, didn't think of that. I was going to reduce the mileage also, but not a biggy - I will I'll just have more equity in the car over time.
Edit - Just double checked on the VW finance site, and if you make over payments you can reduce the loan length or the monthly payment amount. The former would work out slighter better over the loan period, but quite nice to have the ability to reduce monthly payments if making over payments.