Republican Gov. Arnold Schwarzenegger on Monday appointed a new Department of Motor Vehicles director, the Los Angeles Times reports. Joan Borucki, a Democrat and longtime Caltrans official, advocates taxing motorists for every mile they drive by placing GPS systems in their cars.The idea would mean a significant overhaul of how California collects taxes to maintain its often-crumbling roads. Under the plan, the state gas tax — now 18 cents a gallon — would be replaced with a tax on every mile traveled by each car and truck, the report says.Schwarzenegger has not endorsed the idea, though as Californians drive increasingly more fuel-efficient cars, state officials are alarmed that the gasoline tax will not raise enough money to keep up with road needs.Charging people for the miles they drive also worries some owners of hybrid cars, because it could wipe out any gas-tax savings they now enjoy.Privacy advocates worry about the government tracking the whereabouts of every car in California. In one scenario — currently being tested in Oregon — tracking devices send a signal to a GPS satellite following the car, and that information would be used to calculate the tax bill. Other devices send a signal directly from the car to the pump, which calculates the tax based on the odometer reading.Revenue from the gas and diesel fuel tax — about $3.3 billion — will have declined 8% between 1998 and 2005, adjusted for inflation, but the amount of miles traveled by cars and trucks on California roads has increased 16%, according to a February report by the legislative analyst. The California Transportation Commission has said the state needs about $100 billion in road and freeway repairs, the LA Times story says.