Take off your stock rear and measure it, it basically just needs to be a little more than an inch closer to the body of the car because the JDM bumpers are about that much shorter.
My custom rear re-bar sorta looks like a hollow aluminum 2x4... but a little bigger. MY car actually got backed into a few weeks ago and it wrecked my hatch but only scratched the bumper, so I guess it held up pretty good so far.
Bookmarks