Late arrivals
You should post this in the Sixt forum (which has Sixt customer service presence), but it does not apply to Budget (or Avis).
I can't find it in writing, but I am told the following from experience at airport locations and speaking on the phone with Budget CS:
-You can arrive up to 12 hours late from scheduled time (some say 23 hours, but I don't believe that is promised) and pick-up a reservation, if it is going to be beyond that, you need to contact and change the reservation.
-If your late flight arrival would come after the airport pickup office scheduled closing, the Budget office will usually wait 2 hours beyond the scheduled office hours (BUT ONLY IF you had put your flight number in the reservation). I am noticing for airport locations this is becoming a required field more often for reservations. The website seems to indicate they will wait until the last delayed flight, but I would not count on this aspect without calling ahead to confirm.
Rasheed