Tweak has a water-to-air intercooler setup, the "fuel cell" is actually a custom reservoir for the intercooler. It was made to look like a fuel cell though, so don't feel bad.

And my car is Frost White, the code is NH-538.

The visors that I have are no longer available. They were made by a company called "Sinnovations2" but their website is gone now. I bought them in 2005 for $85.