DiRT 3 is actually a really fantastic game. It's been a long time since I've properly played and enjoyed a racing game, but Dirt may top the old Need For Speeds and Test Drive Unlimited 1 as one of my favorites.
I felt Dirt 3 was Dirt 2 broken into piecemeal. Every second race is like "Buy me!". It's like the devs forgot how people like subtlety and DLC to go together.