I have used the type that kinda add on to the mirrors you already have using two rubber straps and like em. Easy on, easy off, and you can really see. I store em in the box they came in, get a name for ya next time I see em. MC
We had strap ons with the lower Pathfinder and I am glad we will not need them due to the height of the X.
Lost a couple mirrors while bushwacking with our high clearance tent trailer, but that may not be an issue (option??) towing an Airstream. I did not like that we had to adjust them each time we used them, and there was a LOT of fibration in wind and higher speeds.
What are the weights on your Airstream? - for when we ungrade - you understand.
I just bought a 22' trailer and picked up as set of Tow-N-See mirrors. They attach to my regular mirrors via a strong suction cup. So far they hold real solid and take about 5 seconds each to put on. I wish they were just a few inches wider and may try to mod them.