SINGAPORE (REUTERS).- Adrian Tan owns two Mercedes sedans and is looking to buy a third car. The 36-year-old financial trader was shopping with his wife on a Singapore street lined with luxury car dealerships and said he may stick with Mercedes or go for an Audi or a BMW. In Singapore, those cars don’t come cheap, selling for upwards of $150,000 with taxes thrown in, but Tan said he was being relatively frugal. “The younger ones who have more disposable income and are doing so much better than before, their willingness to spend dwarfs me all the time. I have peers in their 20s buying high-end Porsches, Lamborghinis and so on.” It’s a trend being repeated across much of the region despite sluggish markets and worries about a double-dip recession. Demand is booming in Asia for luxury cars, upmarket properties, art and jewelry, driven by a seismic shift in wealth from West to East. In their latest annual wealth report, Capgemini/Merrill Lynch said the number of Asian high net-worth