My wife recently took her VW 1.4 Polo in to the local VW Garage for its 4-year annual service. On collection she was told that in one months time, when the car would be exactly four years old, it would be necessary to change the cambelt at a cost of £319. It was explained that this was a time change rather than a mileage one, even though the expected mileage for 4 years could be 60,000. As the car has only done 26,000 miles could you advise if it is necessary to have this work done now?