I reserved a zipcar on May 15th, 2010 for the day...If you book a car for over 8 hours it automatically books at day rate. I called to double check that it was indeed mine for 24 hours. I was assured it was and as long as it was back within 24hours I was fine...When I returned home I parked and locked the car and left it out front of my apartment over night. In the morning I try to gain entrance into the car to drive it back tot he garage and it would not let me in. When I called they told me the car was late and I had to do a whole new reservation to be let in to return the car. I was charged $150 late fee plus the "extra" hours of rental plus the extra hour the following day to return the car. Then I was told headquarters couldn't do a refund. It was out of their control...The company's "headquarters" can't process refunds. Beware this is an absolute scam!!! When I called they said it was no problem as long as the car was returned within 24 hours. Now, I'm being told my initial day rate of $74 has turned into over $225...I think not! This is robbery and they're masters at it! Beware!!!