Petra Ecclestone's New NEW Car -- This Is How She Rolls

Her sister has a brand new Ferrari ... so it wouldn't be FAIR if Petra Ecclestone didn't ALSO have a ridiculously expensive car to drive around -- which is why her new hubby bought her a Rolls-Royce.

The brand new white Rolls-Royce Phantom -- which usually costs around $250,000 -- was wrapped up with a bow ... and delivered outside of the fancy Beverly Hills hotel Petra is staying in while her $85 million mansion is being worked on.

As Petra said herself ... she's not spoiled, she's PRIVILEGED.