Seven million people a year come to Singapore to shop, but where do Singaporeans go? Many get in their cars and drive across the kilometre-long causeway to the border town of Johor Baharu in Malaysia. Groceries and household goods are less expensive here. Two of Asia's biggest wholesale supermarkets are located nearby.
Petrol, too, is so cheap in Johor Baharu that to protect sales in Singapore, customs officials check car gauges on the way out. If the tank is less than two-thirds full a fine is imposed, so some Singapore drivers jam their gauges at "full".
There is also a psychological need for Singaporeans to get off their chewing gum-free and squeaky-clean island once in a while, and experience a more free and easy lifestyle. Johor Baharu has Indian spice shops and Chinese cafes and chewing gum on the pavements and all the aromas of Asia, and some not-so-exotic drains.
Many Singaporeans also go to Johor Baharu for the same reason Americans go to Tijuana in Mexico. It is sin city. There are nightclubs and Karaoke bars with hostesses and private rooms. In side streets dusky maidens beckon customers under signs saying: "Men's Romance Parlours".
But there is much more to this oriental town, founded in 1855 by the Anglophile Sultan of Jahore, Abu Bakar, and now Malaysia's third city, with a population of 300,000. It has modern hotels and resorts centres where South Koreans find a golfing weekend, all-in, cheaper than at home. It has hundreds of sea food restaurants, with abalone, cuttle fish, scallops, prawns, crab and lobster, and dozens of pubs serviced by trucks with familiar-looking harp symbols delivering the city's most popular drink - Malaysian-brewed Guinness.
There is also a magnificent 100year old mosque overlooking the Straits of Malacca, surrounded by gardens rich in pink bougainvillaea and creamy-white chalice vines. The sultan's palace-museum just outside the town is full of magnificent vases and superb Victorian furniture, including two identical thrones, with the sultan's just a little higher than the sultana's.
The Japanese army left these buildings intact when it entered Johor Baharu before crossing the causeway to take Singapore in 1943. They also survived a postwar communist uprising in Malaya which was defeated with the help of Sir Gerard Templar who coined the phrase about "winning the hearts and minds" of the population. (The Northern Ireland-born general once told rebellious villagers, "You're a lot of bastards," which the Chinese interpreter translated as "His Excellency informs you none of your fathers and mothers was married". Templar then said, "But you'll find I'm a bigger bastard," which his translator gave as "His Excellency does admit, however, that his father was also not married to his mother.")
Malaya gained its independence from Britain in August 1957 and formed the new country of Malaysia. Singapore, a mainly Chinese city, joined the Malaysian federation in 1963 but was expelled two years later after communal riots in which many minority Malays were killed.
Tensions between Malaysia and Singapore still occasionally surface, and, indeed, there is a war of words going on at present over some insulting remarks made about Johor Baharu by Singapore's elder statesman, Lee Kuan Yewin.
In a reference to a claim by Tang Liang Hong, a Singaporean opposition politician, that he feared so much for his safety in Singapore he had to flee to Johor Baharu, Lee declared: "Of all places, he went to Johor. If there is anywhere where people can do him harm, that is the place. It is notorious for shootings, muggings and car-jackings."
Lee later apologised but the Malaysian Prime Minister, Dr Mahathir Mohamad, said it was very difficult for the two countries to remain friends. The 21 million Malaysian people, Malay, Chinese and Indian, are intensely proud of their achievements in 40 years of independence, including the modernisation of the capital, Kuala Lumpur, where the 452-metre Petronas Towers is the world's tallest building. They were stung by the slur.
The Singapore Straits Times followed up Lee's accusations by trumpeting the findings of the World Competitiveness Yearbook that Malaysia's crime rate in 1994 had risen higher than that of Singapore, a reversal of the trend of the previous year. (Both countries, in fact, enjoy relatively low crime rates.)
An old threat that Johor Baharu would cut off Singapore's water supply resurfaced in Malaysia, and Singapore politicians threatened to turn off the "pipeline" of Singapore money going in the opposite direction carrying $16 billion (£11 billion), amounting to half of Malaysia's tourist earnings.
In this acrimonious climate, many Singapore organisations opted to skip Malaysia this year for holidays and go to Thailand and Indonesia instead. But Johor Tour Guides Association chairman, Jimmy Leong, said: "Even if there is a drop in Singapore groups going to Johor, it is not a threat to the Johor tourism industry."
Judging by the traffic jams on the causeway the other day, he is right. Because of a slide in the Malaysian ringgit in the last two weeks, Singaporeans can buy even more for their dollars in Johor Baharu. The famous "causeway crawl", I was told, has got worse, with long traffic queues, and Singapore customs officials working overtime, poking their heads into cars to check that the petrol tanks are not almost empty.