Some possibilities of excess sound may come from. In my 2020 LT2, under the front seats, the "rug" is cut for wiring and not mended back together. And...
Tracing Powder or Chalk Test
Clean the weatherstrips and the contact surfaces with cleaning solvent.
1. Apply powder or chalk in an unbroken line to the contact surface of the weatherstrip surrounding the
perimeter of the suspected areas.
2. Close the panel very lightly so as to not disturb the chalk or over-travel the door. Closing the panel
completely presses the weatherstrip firmly against the mating surface.
3. Inspect the applied line on the weatherstrip. The applied line is marred where contact is good. A
corresponding imprint is on the mating surfaces.
4. Gaps or irregularities in the powder or the chalk line on the mating surfaces indicate the areas with
a poor seal.
....just some ideas is all.
Tracing Powder or Chalk Test
Clean the weatherstrips and the contact surfaces with cleaning solvent.
1. Apply powder or chalk in an unbroken line to the contact surface of the weatherstrip surrounding the
perimeter of the suspected areas.
2. Close the panel very lightly so as to not disturb the chalk or over-travel the door. Closing the panel
completely presses the weatherstrip firmly against the mating surface.
3. Inspect the applied line on the weatherstrip. The applied line is marred where contact is good. A
corresponding imprint is on the mating surfaces.
4. Gaps or irregularities in the powder or the chalk line on the mating surfaces indicate the areas with
a poor seal.
....just some ideas is all.
