Go ahead and fix the problem. You need the heat shield. Mine was partially off so I went and took it the rest of the way off before I left work, by the time I got home I checked the trunk under the carpet and it was somewhat warm(30 min drive). All I done was buy larger washers and was able to get the existing nuts off and put the larger washers on with the old nuts and so far no issues. Only takes about 30 mins to replace and you do not even have to remove the muffler to put it back in. Not to mention it just cost me about $1.50 for 4 washers!