This implementation is quite ugly. Just that soft stuff (cell foam plastic?) cut to approximate shape. Mounting secured with zip ties, except for the topmost blocks that are just sitting there. Above the star there are no openings, so that are is not blocked.
(I am not sure how to upload photos here).
In most cars it's easy to drop something just in front of the radiator. In the B250 bumper continues so far back that in order to do that, you'd have to remove the whole bumper. That would be too much work to do twice a year..
So my plan (plan B!) is to do a proper hidden block for 80% or so (here in Finland you do not have to worry about hot weather). Remaining 20% block, needs to be removable. I just have to figure out how that would be done
Options would be this same foam, moving register plate lower, or design a nice 3d-printed cover (not really going to happen).