Yea, before you cut it try this: put eveything on the hangars but keep the band clamps loose. Start at the front where the test pipe meets the straight section, wiggle everything around and make sure the slip fit is all the way in, then tighten that one band clamp. Repeat this process at the other two slip fit joints, and make sure you have slack on the rubber hangars so you're not pulling against them. If you do this, you should be able to get it almost flush.
I'd try that before you cut the zig zag pipe. When I first installed mine, the tip was about 1.5 inches off the rear bumper, and when I did what I described above I got it down to about .75 inches off the rear bumper. I didn't want it any closer because I didn't want to be cleaning exhaust grime off the bumper.