Just the other day as i got out of my XC90 the plastic side panel of the driver seat cracked.
2008 XC90 3.2
I guess its the way i get out of the seat that cracked the part but its clearly a poor design. I talked to the Dealer and they said it has been a common issue so much that the part used to cost $75 and now its sold for $20. I just bought the Part from my local dealer (San Diego Volvo) since they have everything in stock instead of ordering online. I'm not sure if someone has posted this repair before but below is a step by step fix! Its pretty simple.
2 Zip Ties
Look under the drivers seat and you will see the cable that connects to the electric seat memory module. The connector is green. Unplug the green connector (you have to push on the plastic clip on the bottom of the green plastic to get it loose).
Once you get the connector free you will need to remove the two zip ties holding the cable. They are right next to the yellow tape. I found the easiest way to remove these is by using wire cutters and cutting the "one way" part of the zip tie and then you won't have to worry about cutting the cable.
Next you will have to remove the screw that mounts the plastic part to the seat. It is at the very front of the part and the screw head faces away from the driver door. I believe this was a T15 screw.
Once you get this free you can rotate the whole plastic part clockwise. It is attached in the back by a "C Clip" which is part of the plastic. It kind of just rotates around the metal bar at the back of the seat. Just pop it off. Now you need to remove the black clip holding the cable at the front of the part. Its pretty stubborn, i used a knife to bend the teeth back.
Once you get it free you will see the three screws holding in the electric module. Unscrew these three, I believe they were T20 screws, and pop the part out. Now just replace the part into your new plastic side piece and reverse your steps!
Any Questions just let me know!