Petra Ecclestone — Million Dollar Shopping Spree for 3 Cars!

Petra Ecclestonejust dropped a million bucks on 3 cars parked in the driveway of her massive L.A. mansion … which seems odd for someone who’s selling the place and moving to England, right?Petra — whose dadBernie is a billionaire Formula One honcho and her hubby James Stunt who is also a billionaire — is now the proud owner of a $600K Lamborghini Aventador convertible … a $422K Rolls Royce Phantom … and a Range Rover Autobiography that goes for $190K.Celeb consultant Richie Rich hand delivered the wheels from Exotic Euro Cars.TMZ broke the story … Petra went to 5 L.A. realtors and told them she wanted to sell the crib for $110 million — making it the biggest sale in L.A. history — because she was going back to the UK.But we’re told she’s now decided the estate is worth $150 million, so until she gets it she’s staying put.