I’ve had a service plan with my last three VW’s. It’s usually cheapest to buy it at point of order (i.e. when ordering the car) - VW usually have it listed as an offer on their website. When I bought my car last year, the ‘offer’ price was £199 but increased to £269 during the latter part of last year; quite a big price uplift from £199 but still much cheaper than paying for the services individually as and when they’re due.
As @petefaldo has said, it’s a bit of a no brainier. However………if you decide to buy a further service plan for the third and forth services, the cost is significantly higher and only represents a small saving over the price if you pay for services inidividually when they’re carried out.
With VW having launched their new ‘All-in’ product (two year product for cars between 3 and 6 years old - gives you 2 services, 2 MOT’s, 2 years roadside assistance and 2 years warranty. Cost; £33.45 per month), for anyone planning on keeping their car for more than three years, it probably makes more sense to pay for the third service separately and then buy the All-in product.
