FOR someone born and bred in Hongkong, a few weeks spent motoring around the sunny side of the United States could well be punctuated with sporadic attacks of agoraphobia. California - with its vast open spaces, clean beaches and lush greenery- is just about as different from Hongkong as the North Pole is from the Sahara. One of the best ways of getting the most out of a visit to the US West Coast is to run up or down it California style - in a convertible with the top down. Once you get to California, having a good deal of fun doesn't cost you an arm and a leg. Renting a convertible in the US costs less per week than it does to rent a Toyota hatchback in Hongkong for a weekend. With petrol prices hovering around US$1.40 per gallon, the hundreds of kilometres of expressways, highways and freeways that need to be covered to get from, say San Diego to San Francisco, can be traversed for minimum cost . . . even if you're driving apetrol-guzzling Chrysler LeBaron. Stops at hotels along the way cost between US$25 (at a decent, roadside motel) and US$80 (at a Sheraton-type hotel in the city) a night. The California Travellers' Coupon Guide, a magazine you can pick up free at most rental car outlets, is a must. The more than 100 pages of its 1992-1993 edition it packed with information ranging from route maps to hiking trails, listings of amusement parks to restaurants, and details of literally hundreds of motels, inns and hotels all around the state - from theluxuriously expensive to the bargain basement. If one wants to start in the south and work upwards, San Diego is as good a place to begin as any. With attractions such as Marine World and the San Diego Wild Animal Park going for it - to say nothing of its other charms, which range from wineries to cactus-covered panoramic landscapes - this city is as attractive as they come. The wild animal park is well worth a visit. Less than an hour's drive north of downtown San Diego, this 840-hectare sanctuary is home to more than 2,500 animals, many of them roaming freely through its sweeping plains. The US$18.95 fee (for adults; children can get in for US$10.95) includes a 50-minute trip on an electric monorail that runs through the park - complete with guide - a bird show, the ''Rare and Wild America Show'', an all-new elephant show, and, from September, the world's largest display of robotic dinosaurs and prehistoric creatures. A few hours' drive north of the animal park will take you to Los Angeles, around which attractions such as Disneyland, Hollywood and Universal Studios await. While at opposite ends of the City of Angels, both are equally interesting. Disneyland, in Anaheim, is easily one of the most popular sites for Asian tourists, as can be seen by the numbers of Chinese and Japanese tourists who flock there. With its roller coasters, fantasy rides, hi-tech special effects shows and personal introductions to Mickey Mouse, one doesn't have to be a child to enjoy the fun in Disneyland, which stays open until midnight in the summer. Hotels are plentiful in Anaheim, but apart from the amusement parks there isn't a lot tourist can do there that he couldn't do better elsewhere. Two days is, therefore, probably all the time to you need to spend there. Like Disneyland, Universal Studios has its own share of thrills and spills, plus a tour of the whole site. Visitors can learn how special effects in movies such as Backdraft, Back to the Future and Harry and the Hendersons were conjured up, and even takepart in the demonstrations. The drive northwards to San Francisco on the Pacific Coast Highway - also known as Highway 1 - is scenic wonderland. Hugging the coast as it snakes north, Highway 1 goes through such surfers' delights as Malibu, past Hearst Castle - the monumental former home of American multi-millionaire publisher Sir William Randolph Hearst - Santa Cruz and then into San Francisco. If the hilly streets of San Francisco aren't enough to make you dizzy, then the hundred metres or so of the famed Lombard Street that is recognised as the most crooked street in the world. For fun and food, San Francisco overall is hard to beat on the West Coast, and within the city Fisherman's Wharf - Pier 39 in particular - is one of the best places to go. There are many restaurants in this city which, unlike the rest of sunny California, has weather ranging from cool to cold all year round. But for food with a difference, a visit to the Stinking Rose garlic restaurant is a must. If nothing else, it will make a convertible a necessity rather than a mere want for the drive back to the hotel.