Sam Ronson's Birthday Boot

By the time most people turn 31, they've managed to get their lives into some semblance of order — doing their laundry, paying their bills, and, oh yeah, registering their automobiles. But it turns out that for Lindsay Lohan's "best friend," Samantha Ronson, who turns 31 on Aug. 7, that last one has proved to be too difficult.

See, while Sam and Lindsay are busy partying this week with the Ronson family in Miami for the DJ's birthday, back in L.A. the blonde Brit's car has been slapped with a boot by the police — and it's not for unpaid parking tickets.

OK! has learned that the reason behind the fancy orange footear on Sam's Cadillac DTS is she has apparently not registered the car since the last registration expired in Nov. 2007. Additionally, it looks like Sam has used a piece of paper to deliberately covered up the VIN number on the dashboard — a big no-no to traffic cops everywhere.

In addition to the boot that now graces the front left tire of the Cadillac, there's additional decoration on the car in the form of a giant orange sticker on the windshield that reads: "WARNING DO NOT MOVE THIS VEHICLE. This vehicle has been immobilized by the Los Angeles City Department of Transportation for Accumulation of Five or More Delinquent Parking Tickets...This vehicle will be removed and impounded from the street within 72 hours after installation of the devise."

So if Sam doesn't want to make the trek out to the impound lot, she had better hurry back from her Miami merry-making.

To get the boot removed from her car, which has been described as "dented on all four corners, with lots of body damage and scratched paint," Sam must pay any outstanding parking tickets and show proof of new registration. Between fees and penalties, experts tell OK! she's probably going to have to pay in the ballpark of $6,000 to make her car road-worthy again.

Happy 31st, Sam!