Which XM kit for first time installer?

I have a 2006 and I just use the base model XM Roady II. Costco had a whole XM Roady II kit (radio + home adapter/antenna, plus car adapters, etc...) for $79 bucks when I got this last year. I hide the Roady in the front-bottom compartment of the center console. This of course doesn't give me ready access to the Roady but I am tuned into one station (watercolors) almost all the time so it doesn't bother me. If you need more ready access to the controls you might consider something from http://www.mountguys.com/category_s/127.htm or
http://www.arkon.com/xm_mount.php
I was thinking of getting the Akron gooseneck mounting pedestal that attaches to the passenger seat.

I feed the audio through FM channel 88.7. For audiophiles, the sound quality is probably marginal, but for me its just fine. You can improve your sound quality by connecting the Roady to a ground loop isolator and feeding this into the line in port in the center console ( but then its another whole set of tangled cords to deal with).

Reception is going to vary depending on where you drive. I have my magnetic antenna on the metal speaker on the dash and reception is pretty good. It gets iffy in heavily wooded areas with lots of trees and there a few spots in town that are bad but generally I am happy. Reception would probably be best if the antenna was on the roof but I didn't want to have to deal with wires going every where.

(I hope XM/Sirius stay solvent...I would not know what I would do if I had to go back to normal radio!) Hope this helps.

 

I have the VAIS SLX and I'm really happy with it. I have pictures it in my photo album.
http://www.vaistech.com/
You can install just about any radio add-on by following the attached instructions.

 

When I became interested in installing an XM, I first looked at the instructions at https://www.metrotpn.com/documents/PDF%20Files/Prius/Eddie's%20XMRadio%20Install/PriusXMradio3.2.pdf (or http://tinyurl.com/3rmjo) which were too complex for me at the time. I've since discovered the actual connection in the back of the radio can be gotten to much easier using the VAIS 100i instructions that BobR posted.

I have a Pioneer Airware instead and have it mounted on the hump under the dash. You can see it at http://img.photobucket.com/albums/v437/aaf709/Prius/IMG_2228.jpg. I used part of the instructions on the first link to route the antenna wires. I have a DICE for my iPod and the Airware connects to the AUX input on that (the 2005 does not have an AUX input).