It might have seemed that $4 gas finally broke US consumers of their SUV habit. But the Great Recession is proving that the shift has lasted through this period of lower gas prices. There are signs that a permanent shift is underway in the way US drivers related to the cost and value of transportation. Consider car sharing. When I checked in with Zipcar in summer 2008, growth at the leading national car share service was being fueled by high-cost gas. Since then, though, Ken Belson in the NY Times reports that even with lower gas prices Zipcar has continued to expand membership steadily, as have national rivals such as Enterprise and Connect by Hertz, as well as smaller regional chains such as WeCar. In the past year, membership at Zipcar has surged by 30%, with revenue up by 25%, Belson reports. Nationwide, the car share market is expected to grow to 2 million drivers by 2013.