Trailer vent

Looking to install side vents on side of my enclosed trailer 1 on each side , need ideas on where to mount them ? Both up high or both down low ? One low one high? Both at rear or both at front ? Front one side rear one side ?
Whats your end game?
for storage or traveling or at track cooling ?
they make rain covers for the roof vent .
I would put them up high. One front, one back, opposite sides to help air out the prep smell while traveling. Just a thought, some prep(goat) smells are hard to get rid of.
If you have the roof vent the rv rain covers would be good .
quick simple and about thirty dollars .
or like stated front high rear low opposite sides .
expect dust intrusion .
Depends on your expected result of venting the interior of the trailer.

Roof vents allow the possibility of rain water entering the trailer at any time.

A side mounted vent facing forward will apply positive pressure to the interior of the trailer while traveling. If fairly well sealed, dust intrusion will be lessened to a large extent.
Such a vent, sitting still, will have the same effect as any other vent.