We make open hood vent and front vent replacements at www.oemplusmods.com
There's no issues with water getting in because of the channels you mentioned. They basically act as drain channels to get the water out. Even with the stock closed vents, water gets in behind them.
it’s 2 different companies so yes they are completely different. Remnant Performance uses a single pass core which is proven to be the most effective. There’s no info what core this Project Gamma manifold uses
it’s not a replica. We developed this from the ground up. Quality and fitment is superior to all alternatives.
It’s injection molded from PP plastic (same material as diffuser) then paint matched satin black.
It will be double sided tape only yes. We’be been testing it for months and it holds very well. But for added security you can always use some self tapping screws.
We don’t know how much the customs tax, port fees and bonds will be, so the price I mentioned was not taking into consideration those expenses. If they are negligible than that will be the price. If it’s considerable then they might be added on top of that.