A prized possession of one music's biggest petrolheads, Elvis Presley, is set to fetch up to $300,000 at auction next month.Elvis bought the Rolls-Royce Phantom V brand new in 1963 and had it custom-fitted with the latest gadgets including a telephone, electric windows and a microphone.The car was initially midnight blue, but he was forced to have it re-painted a lighter silver because his mother's chickens would repeatedly peck at their reflections when he visited her.