Singer Mariah Carey proved her superstar status on Tuesday (01Apr08), when she brought London traffic to a standstill while promoting her new album E=MC2. Hundreds of fans turned out to catch a glimpse of the Heartbreaker star as she arrived for a signing session at Oxford Street's Selfridges department store. But police struggled to control the huge crowds, and officers were forced to divert cars away from the Selfridges store because of the commotion surrounding Carey's appearance. After posing for waiting photographers outside the store, Carey - who was two hours late for the appearance - was soon ushered inside Selfridges, where two floors had been cordoned off in preparation for her arrival.