NEW YORK - Actor Bob Hoskins never had any doubts that his latest film, Touchstone's $40 million-plus "Who Framed Roger Rabbit,'' would be a smash. "I saw it me self last Thursday,'' he said in his heavy cockney accent. "I think it's a goody.''

Well, if preview audiences are any indication, Zemeckis and Hoskins need not pack their bags. In fact, insiders think Touchstone and executive producer Steven Spielberg have another "E.T.'' on their hands.

"Roger Rabbit,'' a send-up of the Sam Spade genre, mixes live action and animation in an ambitious way that Hollywood has never before seen. Zemeckis notes, only half jokingly, that making the film was akin "to scaling Mount Everest.''

Cartoon characters, most notably Bugs Bunny, Mickey Mouse and Betty Boop, have interplay with human actors. A small army of animators and artists had to be hired. You know this when you sit through the film's final credits - they slog on for some 6 1/2 minutes.

"I psyched myself up knowing this film would be tough to make,'' said Zemeckis, "but I had no idea how tough - I probably wouldn't have done it if I had known what I was getting into. Yes, ignorance is bliss. This was really time-consuming, back-breaking work.''

A lot of the pressure fell on the back of 45-year-old Hoskins, an Oscar nominee for "Mona Lisa.'' But don't talk to him about building a career. "I'll take a job if I like the caterers,'' he said.

As easygoing as they come, Hoskins, sitting in a hotel room sipping on a beer, readily talks about why he took the role of Eddie Valiant, a down-on-his-luck detective who befriends the movie's hero - a goofy cartoon rabbit.

"Because it's something that kids and adults will both love,'' said Hoskins. "But you also have lines in this thing that kids ain't going to get. And that mixture, as far as I'm concerned, is a winner.''

When the choice of casting was first discussed, many at the studio were hoping that they could win over a Harrison Ford type. "But I got the job because I'm a bit cartoonish-looking, don't you think?'' asked the 5-foot-6 Hoskins. "Also, I don't think the typical hero would have been believed having a rabbit for a friend, do you?''

He also got the job because he could do something that many actors could not: He had to play scenes opposite a blank wall (the cartoon characters were added in later).

"We always knew we needed a great actor,'' said Zemeckis, "and someone who wouldn't chafe under the limitations of not having another actor to play off of. And Bob was brilliant at that.''

Hoskins looked no further than his daughter Rosa, then 3, for tips on how to conjure his imaginary pals. "She had this invisible friend named Jeffrey,'' he said, laughing a few times. "She's the one who taught me to see things that aren't real.''

Obviously quite well. "I did that for six months for 16 hours a day,'' Hoskins said. "I lost a little control. Let me tell you, I think people thought I was going a little wacky there for a while.''

When delivering lines to an imaginary character wasn't enough, Charles Fleischer, the man who does the voice for Roger, asked for a rabbit costume. It was easier to play a rabbit that way, he said, and Hoskins agreed.

"We developed a new technique of acting,'' Hoskins said. "When I was supposed to be working with Roger, and he wasn't really there, it was like he really was. I could smell him.''

The strain of this arduous film didn't divide director and star. They sound as though they're about to open a mutual admiration society. "We got along great,'' said Zemeckis, "which is very unusual in any film, but especially this one with all the pressure we were under.''

"If Robert Zemeckis had said, 'Today we march on Moscow,''' said Hoskins, "I would have gone. There was no fighting, no friction on the set, which was unnerving to me. See, on every film, there is always one jerk. It's the name of the game. But I couldn't find one. I got so paranoid - I thought, 'Oh no, maybe it's me,''' he said, laughing.

He calls acting "me day job'' and says that if "Roger Rabbit' 'becomes the runaway smash people predict, he won't be caught up in the hubbub.

"People are already saying the success of this film will make a big change in my life,'' he said. "But I'm still going to be with the same family, the same neighbors in England, the same friends. My life is quite small actually. I do the shopping, I take the kids to school. No one is impressed. I walk into the pub, and it's like, 'Bob, we hear they're calling you a genius. That's great, now buy us a drink.'''

Hoskins recently directed his first film, "Raggedy Rawney.'' The movie was done in Czechoslovakia, and it, too, was hard work.

"I don't know if I would direct another film,'' he said. "If another subject comes up, one that interests me, maybe, but I'm not going to give up my day job. You become so obsessive when you direct. You become the most boring man in the world.''