I installed a pair of Romik RPD-T running boards onto the Ridgeline.

Adds a bit of visual presence to the Ridgeline and makes it easier for my youngsters to get in.
Install was fairly easy, hand tools and ramps in the driveway. All four brackets installed into preexisting holes in the body.
The RPD-T is a very aggressive platform, it will be non-skid in any conditions. It will also be incredibly unfriendly to bare feet.

The running board itself is aluminum, but the brackets are heavy gauge steel. The hardware appears to be stainless steel.