I can help you if you need in the dimension...It'll be a piece of cake. And awesome for you getting it for that cheap!

P.S.
I want to thank you for the amount of detail you have shown here, it has saved me a lot of surprises from going into this completely cold. Usually from my many years of experience in building cars and racing it’s always a step by step process, even when fully thought out there is always some twist to it.

Picked up the Nismo bumper cover yesterday, it’s a beautiful thing.
As far as the splash shield bottom tray$$$ mystery, the $1k+ part number is G5829-1A30A, the one I bought has a # G5829-1A30C on it, I crossed check this with Nission parts on the net and it list for MSRP $144.32 which explains the $115.00 price I paid.

Anyone know the NISMO VERSION P/N for this?
 

So the OEM Base/Sport/Touring version of this part does not extend far enough for the Nismo Undershroud. Anyone know what the NISMO OEM P/N is for this?

http://i358.photobucket.com/albums/o...ps310dcc8a.png

Scruffy,
My thinking was the same as yours, with the ducting to the radiator; I bought a pair of these thinking it was part of the Nismo conversion. Since it was in the dealer Nismo parts list, but in reality it’s the same as the base, I also did some cross checking and can't find anything different, Usually I been finding the part description will say (w/Nismo ) if it is part of the factory conversion.
Does this become critical for normal street car? No! As long as the perimeter of the radiator is seal so airflow will not by-pass it, air will find its way to the radiator at speed do to air pressure differential , also there is a fan on the backside of the radiator to pull air through. If this was an open wheel car aka formula type, it’s a different story. A ducted opening with zero by-pass to the radiator core was critical in decreasing temperature at speed.
What I would do is rivet some plastic or aluminum sheeting to inside inlet of the bumper cover grill area to make up the difference, make it so it overlaps the inner splash shields and seal it with some glued on foam strips.

Yea, I actually have no intention to buy em as they won't do much for the car. At some point I even thought about taking them out when I did the brake duct / Oil Cooler installation. It'd be nice though if someone that has a Nismo 370z could fill in the p/n. How's your build coming along btw? I took dimensions of that Undertray piece for you. If you end up with a Zspeed Undertray, you wouldn't need it as it doesn't use it.

I picked up the Nismo cover on Sat, started prepping the nose to do away with the Nission emblem and fill it in. Have to collect all the fasteners and make brackets ect, so I basically getting started. I have the plastic under tray, The Z-1 tray is nice but I want to install an oil cooler when I do the conversion so I can get it all done in one shot and I can drive this thing as the weather gets nicer here.

So I'm at a project site today and I'm looking at the raised floor and walls and I found the perfect materal we can use to make up the difference between the inner fender splash liner and fender lip, rubber cove base, it comes in black and other colors, its heavy and flexable and easy to cut, it also has a nice finish edge. Best part I got a 4ft strip from the contractor at no cost!

Please do share when you get the chance. My car currently is at the shop getting the paint job already but I'm still missing some Fender Protector pieces which I intent to hack up something. The idea is to use some flexible too.

At this point all I can feed you is my ideas; you are 10 steps ahead of me on this, I am at least a month away before I pull it all apart. And I have Nismo sway bars to install yet. Got a geart deal from Z1, Paid $268 + shipping.:icon17:
I order the front inner splash fenders from the same Auto Parts place you used,
Called them like you said to get the correct part.
Also order the Stillen license plate mount that screws into the tow hook thing.
That needs to be modified and made longer cause the nose is longer. At least this gives me the option of running without a front plate without destroying the nose with a plate mount

Just wanted to make you guys aware of a problem with the front bumper. When it gets painted make sure that they do a good job on the grill area and that they do not paint the bumper first and then paint the grill black, as this will cause issues. Rock chips will make the black paint chip and it'll look like crap!

thanks for letting me know! I will tell my body shop. Do you know if it's a flat black paint they use on the grill?

From photos I seen it looks like a matt black, semi gloss finish.
If he is a good body painter he should be able to find out and match it.
In your case would it matter since you Z is black. My Z is silver and if it chiped, well it would look like crap if that was the case.
Those factory racing mesh grilles look nice, wish someone made them state side so you don't have to pay a fortune, Made one once for an AH bugeye Sprite, alot of work!

For plastic that u can cut, u can use a black trash can..... that's what I used for repair my under tray!

When I had my conversion done, the shop didn't paint it black. I went back and did it myself with PlastiDip. It really is the best thing to use becuase that area really collects the rock chips.

I had 3M clear bra down there before the PlastiDip, and it still got torn up. I simply painted ove the clear bra and have had zero problems. It's really easy to touch up PlastiDip too.