That Car!
Just saw the film on television so I couldn't hit the 'pause' button at the right moment. The first glance at the car's bodywork suggested a Mercedes Benz 540K (my dream car)but a second glance at the radiator soon showed it wasn't. An Hispano Suiza perhaps? I doubt it, because the view through the windscreen when they were travelling at a great rate of knots would have revealed the distinctive HS stork(?) emblem. It didn't. So I will settle on it being an Isotta Fraschini. The radiator looks right and so does the emblem.
Someone will no doubt put me right!