Last December, while I was waiting for my MX, the average production time, based on the data available, was 5 days. The lowest time was 2 days, the longest 53 days. In my case, production time was 17 days.
I assume that the times longer than average mean that an issue was found in QA and the car had to be fixed.
Whatever they fixed on my MX, it was in great shape when it was delivered.