I have never done this before but trying to figure out the best way. I am renting a car this upcoming saturday from PHL. Not sure how long I may need the car definitely need it till December 4th but then may need it for another week. Is it best 2 book for 2 weeks and return early? Anyone know what the rate is if I decide to extend the reservation one week after the initial week? I am a P Circle member with hertz if that helps any.