IIRC in Thailand your car tax is paid on your licence plate and based on the value of your car. If you buy a supercar, Lambo/porsche etc , your tax is 100% of the value of your car! So if you buy one you are in effect buying it twice. The supercar plate does get you certain benefits though such as dedicated parking at places like malls. Which they always allocate right at the front in the most prominent area so obviously it makes the particular mall look luxurious and the place to be. Image and status is everything in BKK!
Anyone with better knowledge of it please feel free to correct me.