I need to replace the foam hood isolator on a 2003 GX325 and I am having trouble removing the old foam that is closet to the backing tape. There is a thin layer of old foam that is still attached to the bonding tape. I have been told that the tape that holds these isolators on is very sticky and bonds very well. I have tried using a razor blade to remove the thin layer of the old isolator without success. I want the new isolator to bond well but I am not sure if I can just install it over the old tape and reminents of the remaining foam. I am quite aware of how flimsey these hoods are and I do not want to crack the hood. Any suggestions would be much appreciated. I am also curious as to the purpose of these hood isolators. My guess is that they cut down on the engine noise.