the Couture lip seems to be made by Carbon Creations
Welcome to Extreme Dimensions :: Inventory Item :: 2009-2012 Nissan 370Z Couture Vortex Front Lip Under Spoiler Air Dam - 1 Piece
which as far as i know is a pretty reputable manufacturer. i did a quick search and didn't immediatley find anyone bad mouthing them. also, i had one of their hoods on my RX7 about some years ago, but think that's not worth much given how much can change in that time frame.