Why can't females backup properly in their vehicles?

LOL  Coffee Drinker has the best answer by far.

Too bad Yahoo trolls don't bother picking best answers...

They're probably distracted when they see you watching them and the sudden urge to vomit at your hideous visage overtakes them. It's hard to park when you're holding back a brown tsunami in your mouth.

Sez a cowardly Anon,  Afraid your Wife might see this?

I have met dames who can back a 700 # Heritage Softail with  their legs, only. 

    "shave"? No. Cover up that atrocious visage...

My wife backs up better than me.  I can"t park backing up to save my life.  So your premise is FALSE and you are just TROLLING.

If you think it's only women who have problems with this stuff, you haven't been paying attention. When my clients come to my house, 4 out of 5 don't know how to drive into the parking spot so they are positioned to easily drive out of it and they don't do it differently even after it's been explained to them. And the men are just as bad at it as the women.

I am female and never have any problem backing up or parking. I have been told that here in Canada, in many cases, you don't need to know how to back up or park to get a driver's licence. They don't make you do it as part of the driving test. That might explain why some people don't know how.

Because the rear view mirror is adjusted to check the hair or makeup.