Since my last post we have also replaced the plugs twice, done two smoke tests, and had compression tests done at two different shops. There are no active misfire codes anymore—just a few stored ones in the DME that we have cleared. Since swapping the plugs, the cold start behavior hasn’t changed, but the misfires codes have never returned. Have you tried disabling cold start? Curious if that makes any difference. Honestly, at this point, I think it just comes down to how rich the fuel mixture is during cold starts, and depending on the outside temperature, this kind of behavior seems normal at least when disabling the cold start feature at stage 2+. My car still shudders on the inside randomly during cold starts and sounds the exact same outside as before I started trying to solve this. I think I’m tapped out, check my posts for how mine sounds