searching for a roof vent

I have a ChevyVan that had a 14"x14" domed, roof vent installed in the roof, over the cargo area. I had to remove the vent to get the van into the garage; the van is just, low enough, within a couple of inches, to make it under the opening. I have had 3/16" or 1/4", I don't remember, plexiglass in place of the roof vent for sometime, now. I would like to reinstall a roof vent, if I could find a surface or flush vent. I can not find one, I have been searching on the internet. The sun roofs that I have seen are much, too, large. Anyone know of a flush or surface roof vent in the 14"x14" size? - MikeyG