I've never used points-only to rent a vehicle. I just checked how many points it would take to pick up a car from Phila. Int'l Airport and keep it for a week. It ranged from 68,000 points to 94,000 points for an economy car up to a SUV. The Hertz cash price for the same vehicles on the website was $327 to $460 as a comparison. I'm betting that the price will very depending on where you rent.