twahl

Mine has the V shaped bike grooves and the scew down top like this one, well actually it looks exactly like that one but mine has Hidden Hitch branding on it, I bought it a couple of years ago. The bikes can sway front to back, but they can't move any close to each other. The rubber padding for the Vs is so far holding up well, even though mine has been stored outside (but under cover). The screw downs are kind of a pain, but there are holes for a long shank lock. Combined with a locking hitch pin, the bikes are as secure as the vehicle is.
I did tie-wrap some inner tube rubber to the upright piece in case of the bikes swaying forward into it. Some similar thinking would protect them from each other, but the top tubes are secure, they aren't going to slide into each other.