Louvers in 3D by Archer Surface Details.
This is what you need for that Salt Lake racer, hot rod or wherever you need to ventilate air.
These aren't decals. They're 3D raised resin louvers that are cast onto Microscale clear decal film. They can be applied onto a finished product as is or they can be painted and the decal film doesn't show.
They are easily applied like decals and add the effect of 3D louvers.
Here is larger view of the louvers, showing a comparison of the sizes.
Five 1/16-1/18 scale sizes are available for the length you need:
.125" (1/8") = 2" long
.188" (3/16) = 3" long
.250" (1/4") = 4.5" long
.292" (9/32) = 5" long
.333" (5/16") = 6" long
I recommend this video so you how to apply Archer Surface Details
Contains one - 2-1/2" long texture strip.