As has also not changed much to default graphics Dirt 2, Dirt 3 looks to me more like a well-intentioned addon.
The existing in Dirt 2 original menu, from where you get to the car einzellnen menu and routes in a kind of camping is, given way to a more neutral technical triangle menu ...
The former pop-rock music also better suited to the rally, as the new partially indefinable electro-pop music with Transformers effects :)
They had the game in Dirt 2 just the feeling of being part of the whole and in Dirt 3 simply works only the race from. Furthermore, I personally find the new racing modes such as Gymkhana boring and rather inappropriate for a rally game. Since I find the Dirt 3 successor showdown conceptually appropriate for such racing modes.
I also find it an impudence which additionally purchasable tracks and cars cost many times more as the purchase price. There were believable 50-60! Either free-to-play with purchasing content, or any content equal to the purchase price. You feel ripped off when only one (albeit the largest) gets part of the game from the beginning.
Who needs to be decided between Dirt 2 and 3 should grab my opinion the 2nd part. Driveability and graphics are both equally good. But the entire presentation and the gameplay is definitely better its predecessor!