I finally got around to installing A/C condenser protection thanks to MKH's how-to thread. This protects against a low-probability event, debris passing through the grill with enough momentum to puncture the A/C condenser. However, the resulting repair would be expensive which might make installing protection worth doing.
A downside would be reduced air flow through the A/C condenser and coolant radiator. The condenser frontal area is much larger than the open area of the grill, so air flow velocity through the condenser is considerably less than that through the grill even before condenser protection is installed. If I drove in a very hot climate like in Phoenix or Las Vegas, I might decide that the risk of less efficient, poorer performing A/C or of overheating the REx engine or coolant-cooled electronic modules might not be worth taking. I have no idea how to assess these risks. However, driving a BEV in Honolulu where the climate is more moderate, I decided that the risk of installing inexpensive A/C condenser protection was worth taking.
I had already purchased a 1' x 2' (30 cm x 60 cm) piece of woven 304 stainless steel wire mesh, so that's what I used for the protective screen. There are pros and cons associated with woven wire mesh versus the powder-coated stamped aluminum grill mesh that MKH used. This woven wire mesh is 74% open versus 60% open for the grill mesh, so airflow through the A/C condenser and coolant radiator would not be as reduced with woven wire mesh.
Stainless steel should age better than powder-coated aluminum whose coating could be chipped by road debris impacts although in our humid, salty climate, light surface rust could form on stainless steel.
Black aluminum grill mesh is more attractive, is easier to work with, and is dimensionally stable (i.e., it doesn't tend to lose its rectangular shape as does unwelded woven wire mesh). Woven wire mesh is not difficult to cut with metal snips, but the woven wire can unweave unless a border is created. Using needle-nose pliers, I bent the wire ends around the outer wire rows to prevent these rows from unweaving. This was rather tedious and time-consuming with a result that isn't especially attractive.
I began by cutting cardboard templates of the right, center, and left grill sections
. I didn't bother shaping the outer ends of the left and right templates to match the shape of the grill because the woven wire mesh would be installed behind the grill where there is room for rectangular ends. I then cut the woven wire mesh to the sizes of the templates and created the borders. Using a right-angle dental pick to help position the woven wire mesh sections, I positioned the mesh sections behind the grill inside V-shaped openings in the grill supports which held the mesh sections in place until I could tie the mesh sections to the vertical grill supports.
To secure the mesh sections, I had planned to use galvanized steel wire that I already had. However, galvanized steel begins to rust fairly quickly in our humid, salty environment, so I decided to use small black plastic zip ties that I already had as can be seen in the left
halves of the protected grill. Also visible is the closed top third of the grill on our BEV which is open on the REx model.