I have a 9 mo. German Shepherd that loves to ride in the back of the 4runner. The issue is that the large back step to get into the cargo area get really slippery when it gets wet or snowy. He's just a puppy now so soon he will be able to clear the step directly into the cargo area but I don't want him killing his joints and stuff falling on that step (or scratching the back bumper trying to get up). Any ideas? I was thinking maybe a line of grip tape or something to that effect.