Another Towing Question
 

I just called Uhaul and confirmed that the rental package for the 6' x 12' trailer does not include mirror extensions. My question is, how necessary are they?

You're towing with the F150, not the sunfire I assume?
If you are a good mirror user and are comfortable towing anything you should be fine with that little 12' trailer. I have telescoping mirrors on my towing truck, but haven't used them except once with a 32' triaxle.
Just make sure to keep an eye on tires and weight distro/shifting before your trip so you can concentrate on driving while on the road.
-Jeremy

Oh yeah:
If you don't have one already the little blind spot round mirrors are nice because you can adjust to see trailer tire, so you don't take out gas station pylons and curbs while turning!

First off, I drive in the right lane and pass in the left lane. When towing, I don't expect to be doing much passing.

I would say that when driving I check the center mirror frequently, and only look in the left mirror when I want to look at something specific. I have my mirrors positioned so that i don't have much of a blind spot. For example, when passing, I first check the center mirror, then I check the left mirror, then I turn my head and check my blind spot. I turn my head to the right to check my blind spot when returning to the right lane. I don't use my right mirror much at all.

I guess my concerns are being able to watch the trailer itself, and being able to see behind the trailer.

The 6x 12 trailer is not much wider than you F150. You F150 mirros will be fine. Uhaul only requires you have mirrors on each side, not the extended mirrors. I've toward a up to a 40 foot trailer with my F150, stock mirrors, with no problems concerns your concerns.

Thanks!

Sometimes I tow an 24 x 8.5' trailer with my stock (small) Chevy mirrors. I have to be a little careful, but it's not a problem.