Honestly, I quite hesitated to put this news on my site. Thanks to "Ireland On line", this old rumour rose again. Not really a first choice rumour anyway. But it apparently came from a Bill Nighy's declaration. According to "Ireland On line", Nighy says of Freeman's casting in the role Adams wished for Grant : "They're both first class. Adams probably thought having Hugh on board would have got the film made."
So let's be clear about that. Douglas certainly though about Hugh Grant who is the most well known British actor. But his first choice, in the nineties, was undoubtedly Hugh Laurie (Blackaddder, Stuart Little, Fry and Laurie...). As, in the eighties, he still hoped to get Simon Jones (the original Arthur in the radio and tv series) on board.
It's not the first time that Hugh Grant's name is quoted when talking about the movie. In January 2002, Ed Victor (Douglas' agent and friend) announced that the movie was not buried, despite Douglas'death and that "Douglas thought Hugh Grant would make a marvelous Arthur and one of the Hollywood actors that's been tracking this for a long time, who wanted top play Zaphod Beeblebrox was Jim Carrey. So if you put those two together perhaps you could see a film there."
In fact an other choice of movie has been made. So there is a kind of opposition between a movie made by and with
Antony Jay (Austin Powers) + Hugh Grant + Jim Carrey
and what we've got now
Garth Jennings (Hammer & Tongs) + Martin Freeman + Sam Rockwell
Personally I've made my choice, even if it's the less commercial one.