Any suggestion for a protection to put on posts in underground parking ?

Question

The posts are ciment and square.

Answer 1

From Encore Commercial Products, Inc. based in Detroit - Column Guard is a cushioned sleeved that wraps around support columns to help protect vehicles from minor damage.  Custom made to fit circular, square, rectangular, I beam, T beam, and double T beam column.  Column Guard has a very durable nylon inner and outer shell with a dense cell foam interior. The 10 oz. nylon fabric is rip-stop, waterproof, fade resistant and mold/mildew proof. The inner foam core is made from 1/2” thick loose cell foam.  Fabric colors: Yellow or black. Custom fabric colors, logos and 4-color graphics are available.  White (silver) or red reflective stripes are 2 inch wide OSHA approved 3M brand reflective tape.  Easy to install in seconds with its Velcro fasteners. This one might also work - Scrape Guard is a highly visible vinyl cover for posts, barriers, walls and beams. (see links below)

Answer 2

Wrap them in bubble wrap or foam! Alternatively learn to park...sorry couldn't resist that one!