I do have a set of spare black plastic clips . The clips are inexpensive at $3 /each ( For a 5 cent piece of plastic ? ) but the vent covers are rather expensive. Replacing the clip after the vent cover blows off somewhere down the road doesn't really solve the problem. Since I installed the screws to hold the vent cover in place
I have not lost one plastic retainer clip .
Murphy's law has again proven to be true !
As a side note , tomato planting is still 4 weeks off for us.
We are supposed to get 3 to 6" of SNOW next week.
34 deg F this morning but warming up to 43 this afternoon.