As noted, the seats are identical, but you need a drill.

The first one you do is about a 4 hour job for one person if you have all the hardware. After you have done one, they go in much quicker.

I will be pleasantly surprised if the guy sends you ALL the hardware you need, especially the plate that goes underneath by the gas tank. When I bought mine, I needed new arm rests and several other parts. I ended up spending as much on hardware at the Volvo dealer as I had paid for the seat. There are also little plastic pieces that go around the holes you cut in the carpet to make the hole look finished. Those are not critical and the kids break them anyway.

When you put the bolts through the wheel wells for the lower seat belt mounts, use stove bolts (rounded heads) so they don't catch on tire chains or scratch the sidewalls of oversized tires. Spray them with aerosol can undercoating.

If you are hauling kids in the back every day, expect to have to redo the wiring in the tailgate hinges every 2-3 years. My kids are now driving my wagon, and I have not had to do the tailgate wiring in about 6 years.

By the way, that third seat is not a comfortable place for anyone over 5 feet tall. If you want to seat seven adults, you need a minivan.

Would a seat from a 245 fit a 240? Do you mean will a 245 fit a 240 wagon? If so, yes they are the same vehicle a 240 wagon is a 245. 200 series, 4 cylinder, 5 doors. Dang it has been a million years since I installed one but in the same respect it feels like I installed a million of them. I do not recall the late model 245's being anymore equipped or drop in ready than the earlier ones. The only thing that was really there was the nut insets up under the head liner where the seat belts attached. All of the rest of the stuff you had to drill holes and put the nut plates behind and shoot it down. Really though it is not too bad to do. The one thing that everyone seemed to flat rate was the plate that fits up above the gas tank that had like 8 bolts that were supposed to go through it. It was common practice to drill out two holes only. I beleive they were 10mm bolts and once you have 2 of them in there 6 more were not going to make it any better or safer. Especially if you figure it was going to have to tear through the floor board to come apart and if it was going to tear through it then 6 more holes in it would not help it. Do you have the factory instructions on how to do it? I have an old 3rd seat kit in the garage (no instructions though) and all of my kids drive 245's and I own my own Volvo repair shop so if you need a hand just e-mail me and I'll see if I can't point you in the right direction.

Good Luck
Mark