I mentioned in my previous posting that I would report back on the sound reduction once I completed the entire job.

My mat/foam install is now completed, and all original carpet and trim is back in place. The soundproofing has made a difference, though not dramatic. I will need to do an apples-to-apples comparison with a stock S2000 in the Seattle area in order to give definitive results. But so far, I think it's a bit quieter, but not dramatically. The closed-cell foam seemed to do more for stopping sound than the mat. Not sure why folks who push Dynamat don't usually emphasize the foam.

Once I get a direct comparison with an un-soundproofed car (hopefully at the next PacNW meet), I'll report back with the final results.

 

Excellent writeup!
Very entertaining as well.
But I'm surprised at the fact that it doesn't make that much of a difference.

Dan