I have a 99 XJ8 base model with base stereo. I had installed sirus in my Rover so i needed it installed in the Jag - need commerical free tunes. My project this weekend was to install: Sirus sat. radio, sirus FM modulator, Kicker amp in truck and Polk audio DXi 6500 6 1/2" component speaker system in rear doors. I have a few pictures of what i have done and a rough outline of what i did. It was a long saturday project. Future audio improvements are front speakers and a noise reducer. Sirus receiver is picking up high end noise.

What did i do:
1. found speaker connections plug in rear seat area. Drivers side by the fuse panel. determined which plug side was input and output at that location.
2. Removed rear lower seat and removed bolts to rear upper seat section.
3. removed fuel tank cover in trunk.
4. Pulled speaker wire from trunk to speaker connector plug in rear seat area.
5. Verified speaker wire - what went to each rear door (LH/RH). Viewed wiring diagram for +/-.
6. Cut wires coming from speakers and spliced to the wires going back to the trunk. Did the same with the wires coming from the stereo.
7. In the trunk area: A)installed bolts with nuts into the position where the plastic insert was located on the fuel tank strap, B) Reinstalled factory tank cover, C) cut a piece of plywood and covered with auto carpet, D) Drilled holes in board and installed over the prior installed bolts, E) mounted amp onto the board.
8. Connected all the wires to the amp: A) speaker input, B)speaker output, C) positive to fuse box in trunk, D) ground to body ground by battery, D) amp turn on was ran from power turn on wire.
9. reinstalled rear seat and started on the doors.
10. Removed door panels, removed woofer and tweeter.
11. Installed PA crossover board in area by door light, install 6 1/2 mid/woofer (straight fit), had to trim tweeter black cover (optional tweeter holder) that it sits in, in order for it to fit in original tweeter holder.
12. clipped the door/ factory wiring for the tweeters off at the base of the connections to factory woofer wiring.
13. put new wiring from the tweeter and woofer to the crossover, used factory wire for input to crossover.

Once i verified everything worked properly, then i took the stereo out, installed FM modulator from Sirus.
Mounted the Sirus receiver bracket in the area of your present buttons. Used small sections of heavy wiring in between the pre-set buttons so the mounting end of the bracket would not be pressing a button.

I hid all my wires in the trunk and was done for now. Later i will do a better job of hiding amp wires. Next month i will replace the front door speaker with same Polks.