same thing happened to me. except, i was driving the legal speed :icon18:..........and a few clips mustve dropped because i heard an incrediblly loud scrape before i stopped and found the thing hanging below my car. damn you nissan!

Over the last few weeks, my plastic panel has continually come off. If you are lowered, and scrape, the clips seem to eventually come out.

The first time, I was on the highway, going around 80-85, and I heard a loud flapping noise, almost like a blown tire or something. I pulled over and found the plastic piece hanging on by one clip. The next day I went to the dealer and bought a handful to replace every once in a while as they fall out.

The problem has become more frequent and my plastic clip bills are going up :) I am guessing the more I scrape, the more imperfections there are on the under body and somehow air is getting into the cavity and forcing the panel out.

The second time the issue happened on the highway, I was headed to LA, going around 85 and heard a LOUD popping noise from the front, like something had knocked up from the road. I pulled over, and the piece had dropped again. The noise was the clips ripping out.

On the Nismo model, I definitely notice a serious aerodynamic issue without the plastic flap. If I go over about 80 - 90, or if I am driving into a strong head wind, a loud vibration noise comes from the front bumper if the flap is not in place. When I get the car on a lift again, I will investigate more, but I thought I would add my story to help.

it sucks. mine flew off on the way from LA back to the bay area. scared the living crap out of me. buy this:

http://www.the370z.com/nismo-370z/48...ml#post1618993

Well, it finally happened. On Saturday, I heard a LOUD Bang, and looked in my rear view to see the panel flying down the highway. The poor driver behind me obviously freaked out, swerved across two lanes, and almost hit the plastic.... I love Nissan right now.

Now if I drive over 65, the entire front air damn produces a crazy loud vibration. Time to pick up the metal underbody panel.

Has anyone else had luck with the metal piece?

If you mean the Z-speed one, it's pretty great. The latest versions of them also supposedly clear big swaybars and oilpan mods better than the version 1 I'm currently running (which was able to stretch anyways, just not ideal).

did my first il change on the z over the weekend, and originally i was just going to keep the plastic tray off. i put it back on due to the belt being so exposed.

i just didn't feel comfortable running the car without the tray.

+1 On the ZSpeed Undershrouds.

Another, unspoken, feature about Joe's shouds is that in the event that you do hit something and it damages the undershroud, all you have to do is hammer it back out in most cases. The OEM Undershroud will explode and shatter when it comes into contact with anything substantial.

They are a bit heavier that the OEM, but for the cost trade off, I think it is well worth it.

They are, but the weight is so close to the ground, if anything it's lowering your CG by .002" or whatever :)