Other mistake: At the start when Crewe's girlfriend says "don't you take my Maserati" Crewe says he has earned it. He then goes out and gets in a Citroen, not a Maserati. Also, a Citroen front license plate appears on the car shortly afterwards which wasn't there before. (00:03:57)
Suggested correction: The Citroen SM model has a Maserati engine.
That doesn't make it a Maserati. Citroën bought Maserati in 1968, but their badge determined the brand, not what engine was in it. A lot of car companies are owned by other car companies to have multiple divisions in their lineup. If someone has a Toyota and called it a Lexus, they'd be wrong, just like it's wrong in this case.