Yeah, the CV's are pretty weak, and are more likely to be destroyed on lowered vehicles. I've smashed mine from launching, but it's a manual, from what I've seen the auto's normally twist the tailshaft before breaking CV's, so it's a bit unusual I guess. With the next set you could get them shortened slightly to compensate for the lower ride height, and/or get stronger ones. I just got stronger internals from Allbins. Not cheap though. I wouldn't say dyno runs would do it, they ramp it up rather than nailing it from a stand still.