The criticism follows complaints from viewers about the ï¿½highly irresponsibleï¿½ footage in their Polar special as the pair tried to reach the Magnetic North Pole last year.
The trust said the scene ‘could be seen to glamorise the misuse of alcohol’.
The motoring show’s executive producer has fought back, saying that said they were beyond the jurisdiction of drink-driving laws in international waters. The trust was also told that neither presenter was shown ‘drunk or out of control of the vehicle’.
However, the BBC Trust said the scene ‘was not editorially justified in the context of a family show pre-watershed’.