Yes PeterJ Dynomatted his Roadster in about 2014
The thread should be still on here but might take a bit of searching
I’ve put Dynomat behind my subwoofer in the passenger footwell, behind my speakers and on the floor on both front footwells
It was just to get a bit more clarity from the sound system and to help prevent a few unwanted frequencies
Didn’t test it without as I put it in with the new system so hard to know the difference but I feel better for doing it
