I do not use extention mirrors with my Element, no. I use the open curtain method, and I tried someone elses mirrors once. They had zero additional benefit.
The Elements mirrors are larger than most, almost trucklike, for a car it's size.
Interestingly enough, I had a less than pleasant experience with a gung ho young CHP officer one my way down the hill the day before Cambria.
He pulled me over for no other reason than to bawl me out for towing with the Element and HAD to inquire about the
weight. I had to get inside to look at the reg. (Which does NOT have the
weight printed on it) He for some reason believed my staements and calmed down after he learned the Burros true self. He THEN proceeded to patrol around the trailer looking for violations. He then told me I didn't need
brakes or two safety chains for a trailer this size.
First he grumps cause he thought I was being unsafe, then he grumps because I am TOO safe.
Not once were mirrors mentioned. And I was happy to see him dissapear in my mirrors as I got back underway.