Hello, I have had the same problem, just never in a Volvo. I used a torx socket for the big torx bolt on the olds cutlass front caliper. I can't remember what size, because I don't use it any more. What I do is, take a hack saw blade and grind the back off untill it fits into the hole of the spark plug. Wrap some tape around the end or use a small handle. Cut through the spark plug just untill you get to the threads. Then go ahead and cut the opposite side same way. Once you have cut through both sides, use a small punch and knock the threads loose. Then give it a good spray of lubricant and using a flat tip screw driver (must be wide enough to reach both cuts in the threads). A grinder is helpfull to make adjustments. I have better luck with the torx tool though. Take a spark plug and cut the end where the other is broke right below the nut. It is where the crimp is for the seal to the cermic plug. Bring that into a NAPA and get the torx that will not quite fit inside. Use you hacksaw tool again and make six shallow cuts that match up to the torx edges. You want the fit snug, but not so you have to drive it in with a three pond ball peen hammer, just enough to ease the plug base out. I uase a vacuum that has a reduction nozzel down to a 3/8 hose (lots of electrical tape), I use that to vacuum up most of the chips that come off from the saw. Use a coat hanger to wrap around the hose and then wrap it around the oil fill, leaving enough hanger to get the hose near the hole (about 1 inch), that gives you enough room to work and hands free of the hose. If all that doesn't work. Napa has a sleeve and tap kit for such problems. The debris though is a bit hard to remove from cylinder afterword. I use a 1/4 inch hose to vacuum out the metal shavings from the drill bit. I wish you luck. I had to do two in a Nissian Maxima. The customer towed it to three different shops before me. Everybody wanted to take the heads off. I can tel you I got the first one out with the hacksaw method in less than 20 min. The second took three differnet approaches before I ended up sleeving the hole. I ran fine when I was done. Once again, PATIENTS is the key. Pauli