Researched the removal of a college decal from the rear window of my 1995 300D. I was about to try the 3M remover suggested here, when my mechanic handed me a can of sosmetal's "Glass Clear". (They also make a really excellent rust penetrant.) I had tried "Goo Be Gone" and several other advertised glue removers without success. I was doubtful about the efficacy of this one, based on the recommendations for some heavy-duty solvents in this thread. However, it worked beautifully. Spray it on, let it foam up, and wipe the foam off. Took two or three sprays on some of the glue, but much of it came off on the first rub. I recommend it highly.

Most of the decal needs to be removed for it to work quickly, so I carefully scraped off the decal that had not been placed on the rear window defroster wires. For the remaining decal sections, I sprayed Glass Clear on and let it sit for a while. When I returned, I was able to lift an edge of the remaining pieces and pull it off, then sprayed again to remove the remaining glue.

Word of warning, carefully cover the rear parcel shelf with towels since the spray can discolor the material.

Tom G