I use ProjektD Radiator guard, so I have no idea.....
I hope the Cox Radiator also uses some sort of bolt in addition to tie wraps? I would be reluctant to use tie wraps on something that will heat cycle all the time. They WILL get brittle and eventually break. Run it over or drag it down the road doesn't sound pleasant......
BTW, ProjectD took 10 minutes, 2 minutes reading the directions, 8 installing it, no tie wraps or finding washers....