Will a Volvo factory installed roof rack from a 1999 v70XC fit on 1994 850 wagon?

Yes it will. I installed XC Eurorails on my 97 wagon. If you're installing a used set, make sure you get the original six screws that hold the rails on, along with the six plastic covers that hide the screw heads. The long strip of molding that runs up the side of the windshield and across the top pops out with no difficulty, revealing the six holes the long black screws go into. With your original piece of molding still in place and the screw holes marked with tape or chalk on the top, set the bars down so the rail screw holes line up with the holes in the top, and then mark the molding where you will have to cut it at the front, about two or three inches under the front part of the rail so the rail will hold it down. Use a hacksaw with a fine tooth blade. Remember that when it comes time to change out the windshield, whoever does it will have to pull the trim up and out from under your rail, so don't cut it so long that the rail clamps it in place.

Although my rails were new, I managed to have a leak in the right rear one. The holes the screws go into are sealed with a black mastic that the screws go through, supposedly sealing out the water. Mine was a very unusual leak, because it would not leak all the time. What happened is that I would drive it, park it warm, come back, and there would be a small puddle of water in the back corner on my plastic floor tray. It took me a long time to realize that when I parked it warm with all the vents sealed, the air would cool and create lower air pressure inside than outside, and exert just enough force to suck the water in. Once the car cooled off on the inside no more water came in. I tried running a garden hose over the top many times and looking inside with the plastic overhead trim removed and could never find it. Eventually it stopped from fine dirt plugging it up. Didn't want to take it off because I didn't know whether I would create more leaks removing the screws from the mastic and re-inserting them again.

Point being, if you have any doubt about how hard the mastic is that the screws go into after all these years, you might want to put a dolop of silicon sealer on top of the mastic the screws go into to make sure water doesn't get past them like it did mine. Dick

We have a '95 850 turbo wagon and a '98 V70 XC and I can't see any difference at all in the body structures from the windshield pillar back. My bet is that they are exactly the same fro mounting teh roof rails. I assume you are talking about the permanent roof rails that run front to back> If so, also try to get the factory cross bars that are made to fit those rails -nice clean fit and easily moved or removed with a special driver. Also try to get the filler strips that go between the feet and front / back of the rails./ Thjese would replace teh full length strips that are there now and are quite likely starting to show some peeling of the black coating on your current car. Alternatively, I expect that the old full length strip can be cut into pieces to refit around the rails.

There are also the "roof racks" that Volvo sells. these are two separate cross bars with integral feet, no front to back rails. These also fit across the 850 / V70 line through 2000 models. Racks have pins that set into small holes on the upper inside edge of front and rear door openings, seen when the doors are open (installed on all models)
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Mike Sullivan ('91 745 (184k), '95 855T (70k), '98 V70XC (83k). Past Volvo's: '85 744 (256k), '86 245 (165k), '86 245 (195k), '88 745 (208k), '93 965 (147k) .