After 4 TSB attempts and a whole new rear end, I still have subtle but noticable gear whine around 40-50 mph on decel. It's more of a slight flutter than a whine. It's not bad enough to keep tearing the rear end apart, but it's still a bit annoying. I'm resigned to accepting it considering that a whole new rear end from the factory still whines a bit.

So, how much does Dynamat reduce rear end noise? Where should I put it to dampen gear whine?

 

It's worth a try. Put some under the rear seat and trunk floor, they're relatively easy spots to get to and it should help.