Also to be fair, any bike carrier off the back of a vehicle will obstruct the tails/plate to some degree.
The angle that the pic is taken from makes it look worse than it is. Tail lights still have pretty good visibility.
Here's a 3/4 view to give a better idea -
Also keep in mind that this is not even a consideration unless you're actually carrying 6 bikes. With 4 bikes or less, there's tons of space behind the tail lights.
Another nice thing is tires are not part of the holding mechanism. Seen plenty of bikes let-go when tires unexpectedly go flat. But then some of our shuttles are pretty rough.
Disclaimer - not associated in any way with NSR, paid full retail.