Guide: How to fold back seats on a 2018 Volvo S90 T8 Inscription
 

WARNING, DANGER, and other caution words: Fold both seats together up and down or you will damage leather where the 2 sides rub against each other. Doesn't have to be exact, plus minus a few inches is fine. Folding both seats together is 100% safe.

I have not been able to find any guides online of how to fold the seats on a 2018 Volvo S90 T8 Inscription. There are no buttons behind the passenger head rest, no handles, no levers to pull... I don't need the back seats down often but now I can fold them when needed and so can you.

Tools: flashlight and something like a screwdriver.

Step 1: Climb in the the trunk, lay on your back on the driver side(USA), head as far back as you can and look up. You are looking for this:
https://cimg7.ibsrv.net/gimg/volvofo...d33d8cac1d.jpg

Step 2: Looking closer you will see this. Move the plastic piece away from the spring. Pop, once side is unlocked.
https://cimg6.ibsrv.net/gimg/volvofo...383b317401.jpg

Step 3: The other side is a bit harder, you are looking for just a small hole. See post 2, Step 8 for location. Same process, move the plastic away from where the spring. Pop, and now the other side it unlocked.
https://cimg8.ibsrv.net/gimg/volvofo...33ec3c2a6e.jpg

WARNING, DANGER, and other caution words: Fold both seats together up and down or you will damage leather where the 2 sides rub against each other. Doesn't have to be exact, plus minus a few inches is fine. Folding both seats together is 100% safe.

https://cimg2.ibsrv.net/gimg/volvofo...fb61a97313.jpg
WARNING, DANGER, and other caution words: Fold both seats together up and down or you will damage leather where the 2 sides rub against each other. Doesn't have to be exact, plus minus a few inches is fine. ​​​​​​​Folding both seats together is 100% safe.

I wanted a easier way then climbing in every time so...
Tools: Same as above plus:10mm socket with a small extension, maybe a magnet to hold the top bolt when putting it back in.
Time: under an hour.

Step 1: With the back seats down take the plastic clips out of the yellow circle holding the #1 panel on both sides.
Step 2: Pull panel #1 from under panel #2 on both sides.
https://cimg5.ibsrv.net/gimg/volvofo...17f98ab99c.jpg

Step 3: Take the 3 bolts holding the latch mechanism on both latches. The top one can be a bit problematic, I pushed it out with a screw driver from inside the trunk while holding the 10mm on it. Pull the top bolt completely out.
https://cimg9.ibsrv.net/gimg/volvofo...f2a7c731f7.jpg

Step 4: Push in side 1, rotate, and pull out the latch with side 2 coming out first (I think).
I was hoping for some electronics inside the latch so I can hook up a switch to the them but its all empty inside. So I went with a paracord as it was in the trunk already and i know it would work. If I were to do it over I would use something that doesn't stretch like a wire or metal cable. I'm skipping a bit to the end but it takes like a 1/2 inch pull to open one side and 1 inch pull to open the other as you have to pull all the stretchiness out of the 3-4 foot paracord before it pops the driver side latch. I was going to tie the 2 together but now I can't due to the different pull lengths.

Step 5: Take of the plastic cover that's over the latch, I broke a few clips while doing it but the clips and cover are just there for looks, and you cant see them unless you take out the latch.

Step 6: Now heat/burn the tip of the cord and twist it into a sharp point while burning your fingers in the process. Push the cord through the hole, and make a knot in the end. I used a double knot and it was a bit large so I moved it and glued it in place so it doesn't rub against anything. If you decide to run the cable all the way to the passenger side as I did, run it before installing the passenger latch. And when installing it make sure the cable is free of the latch. A blob of glue to keep it in place.
https://cimg2.ibsrv.net/gimg/volvofo...4ed1b2c1ab.jpg
https://cimg3.ibsrv.net/gimg/volvofo...9941e096ff.jpg
https://cimg5.ibsrv.net/gimg/volvofo...1b661be5e1.jpg

Step 7: Reinstall everything, the top latch bolts can be problematic, I used a magnet to keep them in the socket so they don't fall out and go sideways.

Step 8: Pull each string to unlock. Fold seats together as one or you will damage your leather seats. You can drop the strings down the first hole to the right of each latch or run both to the last passenger side hole.
https://cimg8.ibsrv.net/gimg/volvofo...1a9bd09daf.jpg

Thank you for all these detailed explanations. I wanted several times to have the rear seats of my Volvo folded down without success, now I can do it.