The issue. All e46’s have a high stance in the rear that even a drop can’t get rid of. I already molded my bumper a couple years ago and wanted to do something to lower the stance.
After a couple photoshops, I compiled a game plan to change this issue and ultimately give the vehicle a much better stance.
What i decided to do was lower the sides, with a slight taper to address the problem. It’s a subtle change, but it makes a HUGE difference.
Ultimately, i’m going to need to fill a gap. So to lessen the gap, I used some Carbon Fiber w/epoxy to Mold the orginal shape of the bumper. Also used some spray adhesive and cyran wrap to protect the bumper and act as a mold release for the Carbon Fiber, as seen here:
One the CF has cured, i pulled it from the bumper and trimmed it up a bit. Using a piece of masking tape as a reference line, i used a razor blade to cut through the plastic.
Now I place the CF piece i made earlier and use it as a backing. This will give me something solid to bond to, as well as limit the ammount of body filler to smooth the gap. Using some high strength adhesive, I mount the CF Piece. The adhesive sets and 30mins, but doesn’t fully cure until 24hrs. So this is where i left off:
Here you can see why i made the backing piece and see just how much of an adjustment i’m making with the bumper.
adhered and clamped in place:
Next Steps will be to adhere the adjusted bumper section to the CF Panel, Form/adjust the wheel arch to match the existing arch, and adjust the exhaust cutouts accordingly.
As it sits, it’s about 1-1/4" lower at the exhaust end and 2-3/4" at the wheel arch.
here i mixed some small pieces Carbon Fiber to “fiberglass jelly”, this makes the bondo more strong, resistant to cracking, and a bit more flexable.
As a result of adding the tiny fibers, it makes the bondo much more thick and bumpy so i use this only as the main base filler.
using no CF Filler in the same “fiberglass jelly” makes a much smoother surface. This is the way it sits right now. I’ll sand this down a bit, then use a finishing putty which is real fine.
made a temporary mold for the exhuast openings using some screen and duct tape. This just gives me the shape i want so i can lay the carbon fiber into it while it cures
Done for the most part, just need to round some edges and tweek it, but it’s primed and ready for paint:
to complete the fabrication of the bumper modification, I formed a Spacer that will help space out the bottom of the bumper between my exhaust tips. This will also help make the bumper more rigid and prevent any unwanted flex in the bumper while driving.
Basically, what i wanted to do was pull the bottom of the bumper down more than it was previously, so it would more closely match the angle of what I had cut and extended on the sides. This should avoid anything from looking awkward having only modified the outter sides of the bumper.
Molded a spacer. Here it is clamped and curing (yes, more CF):
Freshly pulled from the mold:
And Lastley, I used some adhesive and clamped it between the OEM bumper and my ACS Rear Add-on, spacing the section out about a 1/2" more than it was previously:
( I just realized, if you look closely, in the bottom right of this picture, you can see the old CF spacer and the difference between the two)
My next set of pictures should be all done and painted. I’ll try getting to that early this coming week.
Hope this DIY process helps those who want to know what I consider the proper technique wit addressing similar body work. 
