Like many 240 owners, I have to park where leaves can blow down on the car. Many of these leaves somehow work their way down into the fresh air vents and, from there they move down into the interior of the frame where they can add to a rust problem. After some years of trying to remeber to lay a cover over the vents I tried two things. On my daughter's '84 240 I installed IPD's "snow cover". This worked fairly well but some leaves still worked their way into the vent.

Next I tried installing an aluminum mesh such as in my '93 940. I bought a section of aluminum mesh gutter guard. Then I cut a cardboard pattern which would just fit into the widest slot in the vent grill and extend to cover all the grill slots. With this as a pattern, I cut a piece of aluminum mesh to match. I fed the mesh under the vent grill starting at the widest opening. A locking forceps (Harbor Freight) proved helpful in moving the mesh around and then holding it tight up under the grill.

There may be other ways to fasten the mesh up under the grill. I chose to use zip-ties. I heated the end of the zip-tie slightly with a soldering iron and bent this end in a semicircle. This allowed me to thread the zip-tie through the mesh and around the grill. I used 6 ties on each piece. (My '88 has two vent grills while older 240's will have one long grill.)

The result works very well to keep debris out of the vent. You can decide for yourself if you think it looks ok. Here is an image of my car: