How can I buy something through the grey market?

I would like to buy a car and other things but I want general analysis on how to. If possible, please post websites also telling me how to do so. Good Luck.|||Try eBay and Google. You can easily spot them because the price is too good to be true. Beware of buying things off the gray (grey) market. The old saying, "You get what you paid for." rings true in this case.