It would be impossible to make the same film today. A studio would insist on CGI instead of antiquated hand-drawn cel animation, unless it was a part arthouse film with a retro appeal.

Not only that, but if you've ever watched the DVD extras you'll know that trying to get clearance for so many characters from two different rightsholders (Warner Bros and Disney) on screen at the same time was a bigger job than getting most films made in their entirety.

The combination of animation and live action was the flashy drawcard, and for good reason. We'd seen Mary Poppins and Dot and the Kangaroo ten years before but they'd just been badly-lit animation plates over live footage. Director Zemeckis and his production design team went to such lengths to ensure the animated characters interacted with their environment like we'd never seen before it was astounding. For the first time ever, you could believe there were beings called toons that really lived in the world. Just watch the Octopus bartender manipulate real bottles and glasses in the Ink and Paint Club.

The premise against which the story is played out is an inspired piece of world building. It's the postwar boom years in Hollywood and cartoons are big business. Instead of being drawn by humans, 'toons' are real live beings that come from a place called Toontown, just near Hollywood. They come to the set like normal actors, learn their lines ('rabbit gets clunked, rabbit sees stars') and lose concentration when you break their hearts.

One such hapless character is Roger Rabbit (Fleischer), who's married to the disproportionately sexy Jessica (Turner) and can't believe what he's told when photos of his wife playing pattycake with studio boss Marvin Acme emerge.

The photos were taken by private eye Eddie Valiant (Hoskins), who was summoned to the animation powerhouse Maroon studios by cartoon magnate R K Maroon himself to look into Roger's personal problems in secret.

Eddie, who used to love working in Toontown but is a broken mean after the death of his brother and business partner, isn't above taking a couple of grotty spy shots through the window of Jessica's dressing room at the Ink and Paint Club to catch her in the act with Acme for a lousy hundred bucks. Plus expenses.

He thinks that's the end of it and goes back to hanging around the local bar with his erstwhile girlfriend, bartender Delores (Cassidy). But Acme turns up dead and Roger's the prime suspect, turning up at Eddie's office and pleading for help to clear his name. Eddie is reluctant but smells a rat, and uncovers a Chinatown -like conspiracy concerning the city's public transport system, nasty local legislator Judge Doom (Lloyd) and Maroon's shady business interests.

So even without the most realistic animation/live action on screen, it's a riveting noir thriller with so many references to the 50s LA noir genre you'll be hard pressed to pick them all. In fact, the detail is what makes the film so endlessly watchable. The animation style, references to the golden age of Looney Tunes and Disney characters, even tiny turns on the plot come so think and fast you'll never see them all, and if you watch the film every few years you'll pick up something new every time.

Despite reportedly going through 40 some drafts, being hated by test audiences and appearing so directionless at times while it was being made, it's a modern classic.