Happy birthday, Naomi Watts! The starlet turned the big 4-0 yesterday. And we know what her beau Liev Schreiber got for her: a brand-spankin'-new Mercedes-Benz Bluetec! The new, environmentally friendly luxury SUV doesn't hit the market until the end of next month, but Schreiber was able to get one in time for a surprise birthday party he threw for Watts on Saturday night, a source tells me. Details about the party are being kept hush-hush, but I am told the car was delivered with a big red bow on the hood. And I'm sure they got two child seats for their new wheels. Their son, Alexander, is 14 months old, and Watts is pregnant with their second child. She is reportedly due in December. Watts and Schreiber aren't the only celebs driving around in the $50,000-plus car. Other boldfaced names who also already have the ultra-exclusive vehicle include Gwen Stefani and Gavin Rossdale, and Katherine Heigl and her singer hubby Josh Kelley. Schreiber's rep confirmed the gift and the surprise party. She declined to give any details on the bash, other than saying, "Party was attended by family and friends." Source: eonline