Bolts up to oem or aftermarket second cat pipes (use OEM donut gasket on the end of the pipe and tighten bolts accordingly.)
Downpipes. The OEM one on the MR16DDT sucks. Simple as that. Here is a solution to that.
If you look closely, you'll see an innovation that no other aftermarket downpipe for the MR16DDT has ever had: a bolt hole for the oem downpipe support bracket! You do NOT have to use this hole, but this helps prevent an issue that almost ALL MR16DDT downpipes have had: cracking. This added spot on the lower flange takes the weight of the entire exhaust system OFF of the downpipe