Executive Meddling: DreamWorks kept sending notes to Nick Park, telling him to changes things like the design of Wallace's car to appeal to Americans. Ultimately, the only change that was forced upon Aardman was toning down the British accents. Also, they re-dubbed every mention of marrows to "melon", in the US release, because DreamWorks thought most Americans wouldn't know what a marrow was.
What Could Have Been: DreamWorks apparently attempted to replace Peter Sallis with an American actor. Aardman disliked this request, but they came to a compromise to cast well-known British actors like Helena Bonham-Carter, while keeping Sallis in the title role.