Yes agreed on hit and miss luck with all brands...got friends in the M5 who have had zero issues...was gutted tbh as the outright power was addictive and would have been the perfect all rounder
Build date was December 18, easy to spot though as your tyre monitor will be giving off warning signs and telling you recommended pressure is 3.6 bar
Hopefully stay in the RS until next Gen M4 comes out and try again
All the best