Genuine Official Samsung In-Car Holder - Official - Galaxy Note 2, S3, and more - Amazon just £16.20
Yes you can get vehicle docks for cheaper, but if you are sticking in a Note 2 or S3 (a phone worth £300-400+) then you want something a bit more sturdy.
It is a shame that this is just a car holder (no Docking features), but for £16.73, it is excellent quality, very well built, and universal for loads of SmartPhones (not just Samsung).
Great video review here - http://www.youtube.com/watch?v=lee6gdIjP3Q
It is available for cheaper on Amazon Market, but I would prefer the safety of Amazon myself.