ManInTheBowlerHat - in the books, there
was no relationship between Arthur and Trillian, because although he loved her, it was unrequited.
But film-Trillian, as I said above, is a very different character, much more like Fenchurch than Trillian (quirky artist-type rather than rational scientist-type). There is at least a basis for a relationship there that simply doesn't exist in the books.
As for Zaphod, at least Zaphod was much cooler than Ford. Now film-Ford, that was not a cool guy. Can you imagine anyone describing film-Ford as a 'hoopy frood who really knows where his towel is'?
