A few months ago during mud season, my wife brought the car home and said it was making terrible noises after hitting a series of bumps. I was working the outage at Vermont Yankee and after 15 hours of driving/working I was in no mood to deal with cars. The passenger axle had come apart. I tried replacing it the next day to find it looked short and then noticed the engine was drooping on the passenger side. The engine mount bolt on the passenger side snapped and also broke off the top torsional mount. Sweet. I had my mechanic deal with it and replace my timing belt/idler/tensioner pulley because I was working and had no time to do it myself. $700 in parts and labor. At this time he noticed my front control arms had warn out the rear bushings and there was a small hole in the subframe from rusting.
I needed to replace the clutch release fork, TOB and pivot ball, I replaced the clutch too while I was in there. I was going to do this while I replaced the bushings in the front end with prothanes and do a touch-up weld on the little hole in the subframe.
The rear bushings to the control arm also pin the rear of the subframe to the car. The 24mm headed bolt disappears into the frame rail, they were rusted tight and I had no way of getting penetrating oil to them. I resorted to putting an 8' pipe on the end of my breaker bar. After about 1" turned out, the bolt snapped. This is a grade 10.9 metric with a shaft dia. of about 5/8". I broke that... on both sides.

This bolt seemingly had no other end, it disappears into the frame of the car. In the past, they would notch out a section of rail and have a tabbed nut you could get to. Not the case here. Good thing I had one of my friends helping me. I ripped out the interior of the car to pull up the carpets. He noticed a circular indent on the floor just above the location of the broken bolt. I drilled through the floor with a 2-1/2" hole saw.

They f*** planned for this to happen.

I located some 5" 5/8" grade 8.8 standard size bolts with nuts. I got hardened washers and 3/4" hardened washers that I squared up and welded the nut and a tab to to replace the old stuff.

I then proceeded to cut out and replace an entire corner of the subframe that rusted away behind the control arm.

Its all shiny because when I was done I coated the entire subframe in the used ATF from the transmission.
Here's another shot of the broken bolt on the subframe

I spent an entire day on two f*** bolts. Oh, and the clutch swap was the easy part of this.
