SAN FRANCISCO --- Spurred by complaints from a consumer group, California's Department of Insurance is holding hearings on Allstate Insurance Co.'s car insurance rates. According to a report in Insurance Journal, the Foundation for Taxpayer and Consumer Rights has accused Allstate of overcharging drivers $300 million per year. The group contends that Allstate needs to lower its rates by 18.8 percent --- an average of $150 per car --- under existing California rules. The foundation also challenged Allstate's request for five exeptions to auto insurance rate rules. Allstate, however, has said it has already filed to reduce its rates. The company also withdrew its request to charge drivers an additional $15.5 million in premiums, Insurance Journal reported.