The original film was and remains one of the cleverest animated films ever made. Full of lovable characters and with a pervading love for Route 66 and all that it represents, Cars had something for everyone.
Cars 2, on the other hand, used a worn-out British spy parody (complete with the voice of Michael Caine) as an excuse to take the Cars cars to Tokyo, Italy, and England. The visuals were superb, but the plot consisted of one long chase scene. No chemistry seemed to exist between the characters -- even the banter between McQueen and Mater seemed phoned in -- and what is left is enough to entertain children but not enough to cause even a chuckle from their parents.
Up in the Air is certainly not a feel-good film. The George Clooney character makes his living by laying off workers from down-sizing businesses. This, coupled with the increasingly-apparent emptiness of this character's lifestyle, leads to a feeling of helplessness and hopelessness.
But the film is great, because it continually surprises us by breaking rules and dashing expectations. Up in the Air is not epic, but it captivates and fascinates -- seemingly without effort. The actors perform with subtlety ad nuance that is perfectly consistent with the clean narrative style.