Sunday and Monday afternoon I spent some time working on sound deadening KITT's roof. I know there is a lot of debate among third gen enthusiasts as to whether this is worth it on a t-top car. I recorded a before and after video to answer just that (as much for myself as for everyone else).
On two separate occasions when I spoke at length with Rick from RAAMaudio he stressed during both conversations that covering or sealing up all the access holes in the framework of the car will go a long way to cut down the resonance. I took this to heart and along with covering a little more than 80% of the actual roof top (area behind t-tops), I sealed and or covered every access hole I could find.
The large patch in the picture below is covering up an access hole. You can see its outline in the top center of the picture.
I even went as far as sealing up around the indentation where the seatbelt retractor mounts. This may be going further than necessary, but I figure what is the point in covering up all the access holes if I am going to leave these open to resonate?
The center channel for the t-tops also has a series of access holes.
Here is the before and after video comparing the results of the sound deadening. You can hear a noticeable difference. I think it was worth the effort. The nice thing about just covering the access holes is if I need to gain access it is as simple as poking through the sound deadening.