(Adds comment from prior hearing, details on cars in state paragraph 6 and 7)By David ShepardsonWASHINGTON, July 31 (Reuters) - A California state agency on Monday said it is reviewing the privacy practices of automakers and vehicle technology companies amid concerns about the growing volume of data collected by cars. "Regulators around the world have raised concerns about the volume of personal data collected by vehicles that increasingly gather, store and transmit information for entertainment, performance and safety purposes. Mobilisights said it would operate under strict privacy safeguards, sharing only personal data with customer consent and allowing owners to opt out even after consenting