Yes, I use them. They work surprisingly well. They don't have a vibration problem. You can use your power mirror adjustor to adjust them, as they are stuck to the surface of the stock mirror.
They have a suction cup, with a diaphram. You turn a screw that moves the diaphram, to evacuate air from the cup. There is also an elastic loop that goes around your mirror in case the Tow-N-see gets knocked off somehow.
I strongly recommend the convex mirror for the passenger side, possibly for both sides.
I was not sure if they would extend far enough to see behind my trailer, so I wrote the manufacturer, and obtained the following:
"Hello Scott:
The mirrors can extend approx. 8 1/4 inch . Height of the mirror is 5 1/4 inch, width is 5 5/8 inch. The suction cup is about 2.5 inch in diameter. Hope this answers your question. Tens of thousands are being used in Europe, we just were awarded 2nd place for Accessory of the year 2006 by a prominant Dutch RV magazine.
Hope this answers your questions. You can find more info on our web site:
www.tow-n-see.com "
In response to a PM:
My trailer is generally 94" wide, but if you count the bubbled-out taillights and the supports for the awning it is 97" wide.
Generally the obstructed width is 96".
The Tow-N-See mirrors extend the inboard most edge 4" beyond the outer edge of the Taco mirror, and the outboard most edge 8" from the outer edge of the Taco mirror. (The Tow-N-See mirror surface is 4" wide).
So if your 84" outside dimension is correct, the outer edges of the Tow-N-See mirrors mounted would be 100" apart, the inner edges would be 92" apart.
Here is a pic of my Taco with the mirrors attached: