The tie downs in the Road Warrior and Cyclone are both secured the same way. We first use 1" plywood decking and the tie downs are secured directly into L or C channel steel. We use (I think it is called) a 2 1/4" "F" bolt that is self tapping and self guiding directly into the steel through the decking. In other words, if you wanted to add addtional D Rings in a straight line with the other D rings, you would be going into the steel. If you wanted to add wheel chocks or slider tracks left or right of the D rings, you would still be mounting into the 1" plywood. Remember also that the garage rating is 2,500 lbs on all floor plans. Thanks, Mike