For the warranty period, I understand it, but I've heard of people taking 10 year old cars to a Stealership for servicing.
As for technical info, not the case these days, a lot of Manufacturers now give you all the tech help you want, ford are especially good with this.
They realise a lot of...
It amazes me how people still use main dealers, lots of very good independent garages around who will provide you with a much better service at a fraction of the cost, they will still use genuine parts if you're worried about quality.