Miley Cyrus doesn’t celebrate her Sweet 16 until November 23 but America’s Richest Teenager has already forked over fistfuls of cash on a special B-Day gift to herself — a brand new convertible Benz.

The Hannah Montana star plunked down $75,375 on a fully-equipped white Mercedes-Benz CLK 550 Cabriolet late last month.

“Miley wanted special options like parking assist and a cream-colored leather interior, so she ordered the car early,” an In Touch informant claims.