In our experience, the three major fail points were:
-upper inner fender wells where they "attach" to the firewall
-Inner fender wells to shock tower
-Rear shock tower to frame horn

That was with 2 above average chassis'; about 30k street miles driven mostly in CA, AZ and NV; and probably 500 track miles and 2000ish autocross laps split between the two. Your results may vary.