It doesn't come with a dirt cover, i've seen some on dirt track cars, but i think they were fabercated by the owners. i've seen them made with lexan, and others made with alum. I don't know of anyone who makes them but i know that jessel does not. What you see in the pics. is what you get. I also have a Jessel drive that i bought off ebay shortly after i bought the comp unit.
The dirt is something to be concerned about i'm sure.
JMO
Zip.