If that's all you are worried about then just go buy some dynamat(sound dampening material used in cars with loud stereo systems), or similar material, and put some under your carpet over the tranny hump and in front of the seats. I know dynamat is expensive, and I'm not sure how well it insulates, but I'm sure there are similar materials that are cheaper, and insulate well.

Gun it and run it!
1981 CJ5,258,T-176,D300,AMC 20,Dana 30,Trxus M/T 31x10.50, Rancho 5000's, GroundPounderFab front bumper, polyethylene gas tank, aluminum dash, AutoMeter gauges

What this country needs is unemployed politicians.