2001 M3 with a plastic parking sticker on the rear windscreen. Slowly peeled off but the sticker delaminated and the adhesive layer is still on. Cannot scrape it off due to the heater elements. Will appreciate recommendations on what to use to loosen the adhesive but not damage the heater elements.
No personal experience but I would try Goo Gone testing it in a small corner to make sure it wasn't having an effect on the window grid. I've used it to dissolve adhesive on many different materials including plastic and it's never affected anything beside the adhesive.
