They make some excellent plastic fuel cells. We use them in Aviation all the time. I guess the definition of "plastic" can be a bit ambiguous. I have used ATL fuel cells and bladders in cars for decades and they are standard in many F1, Indy, IMSA etc cars. CDT tanks are carbon with I believe a kevlar inner layer and are sealed by CDT prior to shipping. I have 11K miles through one of them with zero issues and zero particulates in the filter screens. I'm pretty sure that an OEM plastic tank for a production bike is probably crap. I have a HRC Spiral Spinner aluminum tank on my 1000RR. That thing will dent just looking at it. Carbon Fiber is really inexpensive from a material perspective and once you have mold, its easy to make parts. I think a foam filled CF/kevlar tank is the way to go and certainly realistic on a 40K bike. A thicker gauge aluminum tank with foam is good as well and they look cool when they are custom and nicely welded. I'm just not a fan of the real thin stuff.
