Following up Gorilla was never going to be easy, not least because the ad was never written with Cadbury in mind in the first place... but nonetheless, I'm massively disappointed--there's none of the charm or wit of the previous film; no sense that the race is an indulgent treat.
My two biggest gripes with it are the choice of soundtrack--far too obvious a song--and the fact that the film shows drivers in the trucks. It would have been far more charming had it been left to our imagination as to whether the vehicles were being driven, or had taken it upon themselves to stage a race.