Flo, there's a retractable toe hook that mounts in the impact shock/crush tube. However it does not fully retract. There is definitely room here for an improved design. In the hot rod world, there are hidden latches that you can depress and the flap opens, much like some modern gas tank flaps. What if there was a very small removable flap or hinged flap with the tow hook securely mounted behind?
Photo courtesy Rennline:
Instead of retracting slightly, what if it was a "Quick release" where you carry the tow hook separately and then attach it under a hidden flap?