Not long after I bought the 240 I noticed that all three tabs on the bottom side of the grill assembly had been broken off, and the center one replaced with a screw and self-locking nut- it was the only thing holding the grill in place on the bottom edge. WIth used grills selling for $50 to $100 on eBay I figured it was worth a shot to repair this once seeing that from the outside it looked fine.
To fix it, I removed the screw. I examined the mount area from under the car and saw that all thee mounting holes (two outboard slots and the center square hole) were easily accessible.
I took some black 1/4 thick Plexiglas and cut a strip about 3/4" wide (just a bit narrower than the mounting slots). I cleaned the bottom of the grill where the tabs use to be, then mounted the grill in place on the car- centered, and aligned fore and aft.
I cut two tabs from the Plexiglas strip, then cut it into two tabs about 1" long. I sanded one edge clean, and coated it with superglue for plastic. If you haven't used this stuff before, it is amazing. I got under the car and stuck the tab through the slot and onto the grill. I held it for about five seconds, then repeated it with the other tab.
For the center I glued two pieces of the tab material stacked for added thickness, then glued that onto the grill in much the same way.
I gave the a chance to harden for a few minutes, then I removed the grill from the car. I mixed some plastic epoxy (this is epoxy specifically made for plastic repairs) and formed a fillet around the base of each of the three tabs where they met the grill for reinforcement. if your grill is missing large pieces, you can use a floppy disk case or similar plastic stick and use this epoxy to reform the missing areas. When it hardens (it only takes about fifteen minutes before it is read to work) you can file, sand, and drill this stuff.
I have repaired a lot of plastic parts on the 960 as well with these two products. They are available at all the home supply stores (Lowes, Home Depot, etc.). I have even used the super glue and floppy casing to recreate broken speaker grill tabs on the 960.
__ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"