Where can I find those black plastic wheel nut cover other than GM dealer

With the guidance of a friend, I replaced my front rotors & brake pads on my 96 Cavalier yesterday. Everything was fine except I made a first timer mistake. I forgot to screw back the 5 black lug nut covers that was left by the driver-side windshield wiper... And when I was on the highway and it rained. As soon as I turned on my wiper, I saw the nut covers flying away...

My local AutoZone doesn't carry them and sugguested me to find it with my GM dealership. Does anyone know other than GM dealership would have it? Even our Pontiac GrandPrix with Alloy Wheels uses the same lug nut covers.

ebay

junkyard...

thats where I get all my stuff! :)