Ivan here from Fluidampr. What I can tell you is that viscous damper technology can be found OEM on 90% of the over the road heavy duty diesel trucks. In addition, Cummins also uses them on their 6.7 applications OEM. There is no damper that compares when it comes to the longevity of the damper and engine. The only reason OEM's do not use them at the light duty truck and car level is due to cost.
This thread caught my eye as we actually have a new "blem" unit 12V damper in our eBay pile. Please contact me at ivan.snyder@fluidampr.com to inquire or to learn more about the advantages of viscous technology. I am happy to answer any questions you may have.