AG System, when you bolted the whiteline swaybar onto your old Civic did you also put washers on either side of the subframe? So one washer between the spacer and subframe and one washer on the other side between the nut and subframe to prevent the nut from being pulled right through the mounting holes in the subframe?

At any rate I think I'll end up going down the path of what you suggested and what big tone did with putting a solid plate over the mounting holes. I believe this setup is much like the Beaks reinforcement kit. Mind you I was reading on another forum and have seen pictures of someone subframe that had a new one torn when the subframe failed with the Beaks kit. Apparently the guy was running Autocrosses and the failure occurred after several laps, but should be OK for spirited street driving.