Mom was from Michigan, Dad was from L.A. I grew up in California. Early questions nailed me in Michigan, later questions shifted to PNW. I feel like I don't have an accent, since everyone on TV and in movies talks like I do. My mom said "pop" instead of soda, and I grew up saying "pop", but switched to soda when everyone around me was saying that. I answered "pop" to the question, knowing that was a big differentiator.
I wonder if any questions would have shifted the map further south.