A little sleuthing by the Post has turned up about a dozen NYC restaurants which have been tacking a 15-20 percent gratuity onto the bill regardless of party size and without noting the policy on the menu. One disgruntled diner, Dazi Chen, tipped off the tabloid after finding a 20 percent "autograt" charge on his check at Midtown's Bombay Eats, where he dined with a friend. "I felt cheated and taken advantage of," Chen fumed. "They're trying to get double gratuity." It's illegal for restaurants to automatically charge a gratuity without notifying customers, and it must be a party of eight or more. But at the River Cafe in DUMBO, two diners from England recently discovered an unannounced 15 percent gratuity on a $400 check, even though the menu reads, "Gratuity and sales tax not included." A manager denies it, but it sounds like a case of tourist profiling by waiters, who always complain about paltry tips from foreigners. Check out the full list of restaurants angling for gratuitous gratuities here.