Euro bumpers, smooth or textured?

[amalventano1 at tds.net (Allyn)]

> Textured bumpers are hard to get clean enough for the paint 
> to stick due to decades of road grime, oil, waxing, armor all 
> (ack). It will likely start peeling chipping off within a 
> year or two. I had mine smoothed and painted about 5 years 
> ago. Not even a chip of the front bumper to this day. It's my daily.

I seem to remember there being some specific primer to use for the type of plastic used in these bumpers... Anyone remember any
specifics on this?

Al