I agree with Peekay64. But similar models (with the new mirror and no vent windows) are listed as 1974+. Probably the story of model year vs construction year...
It won´t rule out the 230.6 [W114] they look the same as the 230.4 [W115], but I would put my guess on one of the four cylinder models since they are more common. So Mercedes-Benz [W115] would be the best to call this one since we don´t know.
Last modelyear for these are 1976, the W123 didn´t appear until spring of 76 and if this car is still in it´s original painting I think it´s a 1976 model. This brick-red colour was new that year if I remember correctly. So if it´s not a dieselsound on the film this car would be a 230.4, the 200 was not sold here due to the new emission rules. However some 1976 cars were sold here as 1975B (not only M-B, common for all makes that year), so we can still not be sure.