Hardwire XM Radio, where to tap? And 12V Lighter fuse issues

[davecoon13]

I got tired of my Sirius Radio and my wife bought me an XM radio for Christmas. The lighter power cord that came with it is too short, so I am going to hardwire the radio.

I ordered a hardwire kit from this site

A few questions, since it has been a long time since I have done car wiring...

1. Where is a good circut to tap into that shuts off when the baja key is turned off? I don't want to drain the battery.

2. Can the negative wire be connected to the carbody or must it be tied into a grounding wire?

3. I am afraid of overloading my lighter circuit since the fuse blew today. My 2003 Baja only has one lighter outlet (unlike later models), so I have a 6 outlet lighter strip (for cellphone charger, GPS, earphone charger, ipod, Sirius radio, etc). Just today the fuse blew out twice (the lighter fuse is tied to the mirrors also), and I figued out that the fuse in the 6 outlet strip was blown, which was causing the car fuse to blow. The 6 outlet strip had a 10amp fuse, but I replaced it with 20Amp (since the in dash fuse for that circuit is 20amp). Also, when that fuse was blown, I noticed that the radio stayed on for an extra 30 seconds when I turned off the key. Is this normal for the radio to stay on extra like that?

4. Where is the wiring that goes into the back of the fuse box, is it a PITA to get at a 12V source that is tied to the accessories (I don't want it always on)?

5. Physically where is the best place to tap a wire? It looks like the XM power supply has a bulky transformer that I will need to hide under the dash?

6. Several posters have mentioned using shirnk tubing. Is that typically shrunk with a solder gun? Does it require solder also? What about using wire nuts or solder or electrical tape?