Personally I dont care for them, but I wonder what is the purpose of them.

Ruin paint.

The bra ruins the paint of the car

They "Lift and Seperate"

They are suppose to keep rocks and gravel from dinging your front end. But the constant dampness and not letting the paint sun bleach uniformly does create a mess over time. I have one for road trips. It comes right off when I get where I'm going.

or,as is the case of my 92, to cover-up a boo-boo

The purpose of a bra is to protect the front end from rock chips, but actually the bra makes everything worse, since it will build dirt up behind it, and grind it into your paint, therefore ruining it.

I definitely don't like them things now .

Like I said, I only have mine on during an actually trip. I hear horror stories about the clear 3M ones too. After time you peel it off, and off comes paint chips everywhere it got hit by something. It'* actually worse than leaving it alone.

or peeling clearcoat, as is the case on the GP

Well...I have mine, and like mine. I drive a lot on the freeways and what not, so I need the protection. No ill effects, but I take care of it.