Detroit diary: when launches go wrong - Mercedes
For those that don't know, the Liverpool-born actress plays the role of a sex-mad New Yorker in the show, and she arrived on stage in a suitably figure-hugging red dress.
That alone meant she was forgiven cringe-worthy gags about enjoying being surrounded by so many men, and the fact she liked the GLK because she's 'always likes things in small packages'.
Once she had said her bit, Cattrall remained on stage as the conference moved on and Dr Dieter Zetsche, the moustachioed head of Mercedes Cars, tried to talk about the car.
The wisdom of this is uncertain, as the male-dominated audience seemed to have trouble concentrating.
When the conference ended and everyone was invited up on stage to inspect the GLK and SLK models just unveiled, the assembled journalists swept past the cars to surround Cattrall.
Rule number two: if you have an attractive celebrity on stage, get them off again when you want people to look at your cars.