Thanks to everyone for the postings and assistance it was a good father/son project.
Install was a success and overall it took about one hour to complete. System works great; all speakers function properly and the bass is quite apparent. I would not recommend this project for someone with limited or very minimal mechanical ability.
If you purchase a subwoofer off of the internet (new or used) make sure that you have the wiring harness, foam strips to cover the connections and one washer included. To the best of my knowledge, the Liberty is not prewired and you MUST have the factory harness to make the connections.
Feeding the wiring harness through dashboard and making/sealing connections is a bit of a challenge due to limited space and avoiding damage to radio/bezel/dash etc. Also, the radio does not want to slide back in place with additional wiring harness. Push the new harness off to the left side along with the new fuse holder. One thing to remember is only connect the harness to the power supply (auxillary outlet) after the radio is re-installed. Definitely test the radio and subwoofer before you completely reassemble and proceed with mounting subwoofer beneath the seat. Also, you can make adjustment to the bass & volume on the subwoofer itself. There are two small and almost hidden black phillips screews on the back & side of the subwoofer which are not mentioned or seen in the instructions. You must tune and adjust before installing beneath the seat. Adjustment screews are in a very tight space and you may want to rotate screws counter clockwise as a place to start your adjustment. Not very difficut to tune, just limited space in which to work. Once you are certain that it works and you have the right sound, disconnect subwoofer and then run harness along the drivers side of the consol. Remove metric bolts from drivers seat and install subwoofer. Note: front left of drivers seat you have the seat frame, then the washer (as supplied in the kit) on top of the frame and then the subwoofer bracket on the very top; the bolt is then attached. On the right front side of the seat the subwoofer bracket installs beneath the seat frame. Left rear subwoofer bracket mounts on top of the seat frame. There is no right rear mounting bracket to attach whereas it is freestanding. Torque seat bolts (35 pounds) back in place and you are good to go. Good luck...