Curb-alert experience?

Anyone had experience with Curb-Alert front bumper protection? My 335d M-sport did not allow me to order front bumper PDC, so I worry about crunching the underside of the low bumper on those concrete parking wheel stops. This sounds like it might be a solution if it could be installed unobtrusively.

http://www.curb-alert.com/index.php

I do it all the time.

Anyone remember these?

http://en.wikipedia.org/wiki/Curb_feeler

Complete how to:

I do remember those and recall that they worked extremely well for side protection, since they used the car's sheet metal as a resonator. I guess I could stick a couple low on the front grill like a cat's whiskers. No messy wires, holes in the firewall, or fuse box connections to fool with either.

yeah I remember those and BTW they worked better than anything else!!