DJAlan

MKARESH is right! You should adjust your mirrors so that:
1) The rearview (center) mirror shows what is directly behind you
2) The side mirrors show what is on the SIDE of you (not behind you)
I set mine by looking in the rearview mirror as a car starts to pass - when it's just about out of the view of the rearview/center mirror, I SHOULD be seeing the vehicle show up in my SIDE mirrors... Also, it should STAY visable in your side mirror until you can see it in your peripheral vision... (if you have normal PV that is)
If you need to 'adjust' them for backing up into tight spaces, do it right before you back up! Then change them again when you don't need to back up anymore...
Yes, it's different than driving a big rig - why? Because there's no REARVIEW MIRROR on a big truck - but that's also why they put those mirrors farther out than cars AND why most have blind spot mirrors as well...
But set those mirrors as above and get used to it... You will be happier and not scare as many folks when you change lanes without looking over your shoulder first (like you're supposed to do but most don't)...
Besides, this way you can see that cute chick's/guy's face better as they start to pass you...