Make interior quieter without insulation
 

I also posted this in C6 General, but I don't actually know if the C6 and C6Z have the same hatch/hoop layout, although I'd be surprised if they were different.

I don't know if any of you might want to try this, but I'm posting here just in case. I used to have a C5Z and after I installed a foam insert that separated the front part of the car from the trunk area, the car was much quieter. Not Lexus quiet, but noticeably quieter. Now I have a C6Z and there was no way to put in a similar foam divider, since it's a hatch design instead of the fixed roof coupe of the C5Z. I guess I could have stuck a foam divider in, but then I'd lose my rear view mirror, and that was a no-go for me. So what I came up with is a 1/4" Plexiglas divider that also make my car noticeably quieter than without it. To make it as noise blocking as possible, I put a 1/4" wide rubber U-channel around the upper part that contacts the plastic of the hatch hoop. I made the pattern by using a piece of cardboard that's 1/2 the width of the hoop opening, and doing a check/cut./check/cut routine until I was happy with the fitment. The bottom of the plexiglass fits right up against the ~3" wide ridge behind the seats, and I then forced the upper half into the hoop area, and the rubber edging has kept it in place now for going on 2 weeks, with no sign that it's moving.

BTW, I installed it vertically at first, but the reflections from the front of the car was making it too difficult to see when using the rear-view mirror at night. Basically, the car headlights and any other lights would show a reflection on the plexiglass such that using the rear-view was just too difficult.

One thing I forgot to mention is that because the area is split into the passenger area and the storage area, the A/C drops the temperature much faster, and even the factory speakers can really put out the bass. On my way home from work yesterday, it was 111 F, and in the 30 minutes it took to get home, the temperature in the cabin actually got too cold, and I had to turn it up a few degrees! That simply never happened before putting in the divider. However, it also means the hatch area effectively doesn't get any A/C cooling, so it gets hot back there.

https://cimg3.ibsrv.net/gimg/www.cor...aaf7441754.jpg
Upper part of divider, with rubber edging pushed into hoop area.



https://cimg4.ibsrv.net/gimg/www.cor...54afa8e617.jpg
Lower part of divider that sits on carpet behind ~3 ledge behind the seats.



https://cimg5.ibsrv.net/gimg/www.cor...90629e7760.jpg
Cardboard pattern.

That's a pretty good idea actually. You should patent that.