Bought it when I bought my 1.4 TSi. Although the new belt drive engine is completely different to the old chain drive the number of horror stories I had read over the years made me nervous and since I keep my cars about 5 years normally the extra cost was well worthwhile since provided you bought it before the car was registered the warranty covered exactly the same items as the first 3 years. Since the DSG box has been very troublesome in the past I think it is well worth buying, some sites still recommend selling any VAG car with a DSG before the warranty expires.
Also bought the service plan, quite a saving over the cost of individual services. Costs me £10.91 a month for 3 years. I was not aware at the time you could get longer plans, if I had known I would have bought a 4 year one since its not much more and the 4th year service is expensive.