Only issue we had was when the wife, distracted by wieidly 6mnth old & 2.5 year old kids in the back seat, forgot it was on the roof & drove into a multi level carpark, that was too low, & ripped it clean of the roof, carrier and all.
by the height indicator beam.
That was 5.5 years ago now, but still run the spare up there with no other probs at all.