Grand Aero Towing mirrors -- clamp easily and quickly onto OEM mirrors, hold the adjustments you made to them between taking them off and putting them back on. They are the best add on tow mirrors I have ever used. No problems whatsoever with them. They haven't left a scratch or a mark on my vehicle, and make no noise. Vibration level is very very low.
Clicky hereRe McKesh mirrors, I'm glad two previous posters had good luck with theirs, but my experience was completely different. The straps sang in the wind so loudly and persistently that they became unusable -- they were so loud it would give you a headache, drive you crazy, or both, and nothing I did would stop the singing. The straps also began to wear a little bit of paint off the doors.
Then if I rolled the windows down while they were on the vehicle, the brackets would mark and damage the windows, so I couldn't roll the windows down once they were on. I understand it is possible these problems I had with them may vary from vehicle to vehicle. I happily sold mine on ebay, once I got my Grand Aero mirrors.