My S3 Spider developed a noticeable vibration between 40 and 45 mph this autumn, and so after the driving season I put it up on stands and found that the center support bearing on the driveshaft seems to be toast. The shaft flops around from side to side quite easily. I'm trying to remove the front shaft but the bolts connecting the flanges of the front and rear driveshafts (just aft of the center bearing) will not budge. Other than a bit of surface rust, the nuts and bolts are in very clean condition, not corroded or rusty. As the nuts on this flange connection seem to fit tight against the shoulder of the flange, and as such seem to be locked in place, not able to rotate because they would jam against the flange if they did, I am trying to turn the bolts out. Are the nuts supposed to fit so snug against the flange, or did a PO install larger bolts during a previous repair? The nuts and bolts are both 13mm hex. Is there a recommendation as to the best way to loosen these bolts? A favorite penetrating oil? I'm afraid I'm going to break each bolt if I try to torque them even more. Any ideas?