Hello,
Colin, the H6 might very well have plastic everywhere. Plastic is like the OEM version of stickers for rice/wheat/whatever-boys. The more they put on the cars, the happier they seem to be. However, the biggest function of that plastic cover on our cars is to keep anything from getting on the belt since anything, especially oil, but including coolant, can degrade the rubber or induce slipping and cause a fatal engine death
With a chain, you don't have to worry about that kind of crap. There's still a cover, but you don't have to have something like 20 gaskets included with the cover (which I had the pleasure of figuring out recently when I rebuilt an engine and needed to replace that cover).
Weight is a good point, though. I guess that's another reason to avoid chains on low torque cars like 4-bangers and why it's okay to use them on the H6.
Anyone else read the article in automotive engineering? They seem to love new engines and always yap on forever about every new feature
Joel