The rubber is the same. The Nismo has an extra extension mount on that left side hanger that drops it down (it's metal). I know because HKS made supplemental instuctions for Nismo owners for thier exhaust on my car showing to remove it. For a non-nismo you'll want to get that from the owner or buy one.
I have a PDF of the instructions from HKS but can't link it. If AK or someone wants to PM me I can email it so they can stick in here.
Here are some pics I took. It's been a while but I believe this is right. here you can see the standard mount (the first horizontal lip with half the nut showing on the upper part of the pic) Notice there is a second extension bracket bolted to it (second horizontal lip with nut). The second lower bracket is unique to the Nismo models:
Here's what it looks like with it off (which is what I'm sure all non-Nismo models look like stock):
Hope that helps.
Edit: Supplemental instructions attached.