I read this thread very carefully as I have a similar situation in Australia. I was looking for a rental car pick-up in KNX, and drop-off in PER. Only Avis showed availability. The car was initially on request but they confirmed the rental in the 72-hour window. I must have been so happy that I finally found a car that I forgot to change the pick-up drop-off times. So I have a confirmed renteal for 10AM-10AM while I will pick-up the car around 11:30 and return it around 2PM.
Should I update the reservation (I cannot do it online) or would it be better to make a new reservation with the correct times, or just leave it like that?