I enjoyed the first movie, and I didn't think it was too bad. While having the characters as cars with eyes and mouths wasn't the most original idea ever, it was still executed fairly well. I didn't expect it to have a sequel though. Overall, I think the original is the better movie, Cars 2 seem to have fallen into the trap of having too many cliche elements. It's still an enjoyable movie, and fun to watch. The animation is top-notch and I was impressed by the London scenes, the environment was beautifully animated. Cars 2 is more action orientated, and surprisingly, guns are heavily featured, as well as explosions and intent to kill. This is more like a comedy spy film than a kid friendly animation. I'm not completely sold on this new direction. Anyway, there were some good humor, especially when the creators had some fun in getting around the limitations of being a car and making the characters do what humans normally do. There's a typical underlying message here. The ending was fun and it was a heartwarming moment. The revelation of the mastermind behind everything was disappointing though, the villain didn't seem to fit the character. While it doesn't have that special feel like other Disney Pixar films, it's still a decent film and a blast to watch.
Of note, the Hawaiian Vacation short set in the Toy Story universe as a special feature in the DVD was brilliant and funny. It stole the show and felt much more fun than the Cars 2 movie itself...