Modify Reservation... Why is it called rebooking?
 

I'm not sure I'm understanding the Sixt site.

My reservation is 2 weeks away. I have put the wrong pick up and drop off times for my car (basically they are opposite of what I need them to be - pick up at 9am drop off at noon) but when I attempt to swap the times, it appears as though I'll be charged in full again.

Anyone have experience with this? I'm not really trusting the system... There is no customer service to ask, the customer service is automated and only refers me to the website that seems to want to charge for the rental again... another $600 or so. I'm really trying to dump avis and this is my first rental with another agency... Any help is appreciated.

Did you prepay in the first place or was it a pay-later reservation?

I prepaid for the lower rate

You should check the terms and conditions for your prepaid rental. If you can cancel with no penalty, your best bet would be to just do that and book a new reservation for the new times. Keep in mind that prices may be different now than when you booked.

That said, rental companies understand that flights can be delayed or arrive early, so it's generally not a problem to show up a few hours early/late for your reservation if at an airport. It sounds like you'll be picking up 3 hours early and dropping off 3 hours later than scheduled. This shouldn't be an issue, but keep in mind that it's likely to add an additional day to your rental so there likely will be some adjustment at the rental counter.

That's true. I guess the painful part would be waiting a few hours to pick up the car to avoid an increased rate ...

Or pick up when you arrive and return by the same time you picked up to accomplish the same thing.

That would actually work! Thank you