Dynamatting

[KCALB SIRAY]

You'll have to remove the seats to completely remove the carpet to start with.

What is your ultimate goal here? There are a couple of ways to look at this; Road noise, use for car stereo, insulation. To get your surface area, see the attached picture below.

No matter what your goal is, the outcome will obviously be a quieter interior. Here's a little trick and will save you money if you prefer. Dynamat Extreme costs about $280 for 36 sq ft. That's close to $8 a sq ft. All you would need to do to provide a simple sound deadening is hop over to the Home Depot or Lowe's and pick up a few rolls of Frost King Self-Stick Foam Foil Duct Insulation (or the like). It costs around $15 to $20 for a 12"x15' roll. At the high end that would turn out to be around $1.30 a sq ft.

$1.30 per sq ft
vs
$8.00 per sq ft

I've used this on many cars from muscle cars to imports and aside from the reduced road noise, I've had cooler summers, warmer winters, and it doesn't weigh as much as the Dynamat. Hope this helps.