From the service manual -- condensed version -- the J 38778 is just a normal trim clip tool -- the carpet comes in 3 pieces; driver & passenger front and rear
Caution: In order to prevent SIR deployment, personal injury, or unnecessary SIR system repairs, do not strike the door or the door pillar in the area of the side impact sensor (SIS). Turn OFF the ignition and remove the key when performing service in the area of the SIS. Remove:
rear seat cushion
front carpet retainers
rear carpet retainers
center pillar garnish moldings
Using a J 38778 disconnect the push-in retainers at the rear ducts.
Carefully lift the rear carpet in order to disengage the front floor ducts (4) from the rear floor duct assembly.
Remove the carpet from the vehicle.
Using the J 38778 disconnect the push-in retainers from the air ducts to the rear carpet.
Remove the air ducts from the carpeting.
Our carpeting has about 1/4 - 1/2" of insulating foam attached to it. Most aftermarket companies won't put this on, or have something quite inferior. Go OEM if at all possible...my guess is it won't be too cheap.