Creator Backlash: While neither had ever spoken ill of the film, Nick Park and Peter Sallis have separately stated that the characters of Wallace and Gromit work much better in shorts than in a feature.
Executive Meddling: This film was really where Aardman began to feel the pressure from DreamWorks Animation which would eventually lead to them breaking off their contract two films early. Jeff Katzenberg pushed Nick Park to "Americanize" some aspects of the film, such as the designs of Wallace's car and even replace Peter Sallis with a more famous American actor. He also wanted the film to have Denser and Wackier humor in the wake of the success of Shrek. Aardman politely but firmly dismissed these suggestions, eventually compromising by casting well-known British actors like Helena Bonham-Carter, while keeping Sallis in the title role, and toning down the British accents. They also re-dubbed every mention of marrows to "melon", in the US release, because DreamWorks thought most Americans wouldn't know what a marrow was.
Orphaned Reference: The "veg bad" spiel that Wallace gives to the rabbits in order to brainwash them is meant to completely echo the "cheese bad" spiel he gives to himself when the Mind-Manipulation-O-Matic first appears. In the final film, Lady Tottington calls him before he turns the machine on.
What Could Have Been: Originally, the design for the Were-Rabbit was much more ferocious-looking and bigger, but was toned down to make it look less scary.
One version of the ending had Wallace left with the rabbit ears after changing back from the Were-Rabbit note Which is why Lady Tottington's mouth movements don't match when she says "The Rabbit's gone", her original line was redubbed, necessitating Wallace and Hutch going through the Mind-Manipulation-O-Matic a second time to change Wallace back and leaving Hutch a normal rabbit again.