I have a 3" catted downpipe that i'm in the middle of installing and found out that the lower heat shield does not fit around the diameter of the new cat! I've read of others wrapping the downpipe which i have now done but i still want to run the upper heat shield. The downpipe is also ceramic coated as well.

My question is how do people run the upper heat shield with the lower if the upper shield bolts along the front to the lower one? Will it not rattle around to much with the securing points?

Should i trim the lower heat shield so the top portion is still there for the mounting points? (This is what i'm leaning towards)