Has anyone found an alternative to the houdini strap that works? My DS started getting it undone at 18 months and then sort of forgot about it. Since just before he turned 2, he gets it off as soon as we drive off. Then often tries to unclick the car seat buckle 😁. I've tried using two houdini straps as well as tightening the straps on him as much as I can but he still gets out in 4.7 seconds.