Have seen them on different upper or lower corner
locations and was wondering what would be the
most effective placements on both the driver and
passenger side?

 

For us, the best location was in the middle, toward the door.

 

Was watching Home Shopping Network (HSN) commercial
and they had them upper corner, closest to the car for both
sides. I'm going to try their suggestion but make sure that I
haven't permanently set them.....in the event I have to try
something different to feel comfortable with the set up.

 

in a spot where you cant see

 

Think before I had the euro blind spot mirrors I had mine on the very end top corner towards the door. They fell off over time, took a couple years, I think the heating element in the glass over years ruins the tape and they fall off.