Disable Sound Generator With Minimal effort
 

I will be picking up my new '14 BRZ Limited this Friday.

Would like to disable sound generator with minimal effort- Could I just plug the hole under carpet in passenger's footwell using a 7/8" nylon plug?

Yup. You could also take the plug from the glove box for the power adapter and use that as well.

This is the cheapest and easiest way to do it.

This is what I did. The difference in sound is huge on high rpm. haha pretty cool stuff.

Others have posted saying that very good plugging of the cabin hole is just as good for noise reduction as deleting the entire sound tube itself. So plugging should do the trick, but you'll still have that unsightly tube under the hood. Add rubber or foam behind the plug to be more effective.

You can simply plug the hole with a 3/4" nylon plug, and with a flathead screwdriver and a 10mm socket you can take out the sound tube and plug the hole with a 1.25" pvc plug (not cap!). Can be done in < 5 minutes.