Scott,
It sounds like you have too much traction.
Do what I do, run BFG Euro T/A bricks and you'll never develop enough grip to break anything. (That is, unless the thing gets away from you and hits something.)
But seriously, I roadrace a Legends car, and I'm continually finding weak points. My aim is whenever something breaks, fix it stronger that it was before and move on to the next weakest point.
We last ran at Kershaw, SC and of the 13 or so Legends there, I think there were 4 broken axles due to the rumble strips along the track edges. I quickly learned to stay off the danged things, and whenever I did hit one, I just lifted and coasted across. (Better to lose a position than to go out broken.)
When I got home and inspected the car, I found a cracked frame member at the top rearend link attachment. The rules allow us to double-shear that mouont, so when I fixed it, I did just that. (Next on my list is to double-shear all the rearend links.)
Another point, always inspect the car after every event. Tighten all suspension and steering related fasteners, clean and lube everything. This often allows you to find small things before they turn into big things. High performance cars demand a LOT of maintenance if they're to be safe and reliable.
Good luck,