What do you guys use the spottter mirrors for on the big telescoping mirrors?

I currently have mine set to view cars which are close to me but out of sight of the main mirrors.

 

When I'm unloaded I use it for the same thing. When towing I'll use it to see cars in my blind spots (main reason for spot mirrors existance), but I'll also use it to keep an eye on my trailer tires. Coming back from Indiana in July I lost a trailer tire and had I not been watching the mirrors I wouldn't have caught it as soon as I did. Suprisingly I lost the entire tread (never did find it) and I never felt a thing, I got lucky and saw it separate in the mirror.

 

I use them mainly for spotting cars in my blind spots, but also use them to keep an eye on the inside trailer tires when I go around tight corners. They're very handy for avoiding costly rim repairs caused by hitting curbs.