Looking for some advice on panoramic rearview mirror. Since surgery my rom is just not what it needs to be to safely check my blind spots. Someone posted about a panoramic. I googled it...but come up with a lot of different options. They range from 12" (doesn't seem very big) to 34" length (seems ginormous)...and all different types. I would like one that just clips on and off. Hoping that it is something I won't need to use forever. Any input from folks who have used these would be much appreciated.