When 3 degrees or below on a cold start, my 328i cranks and starts perfectly, and the revs begin to drop as normal. But when they hit 1000rpm, there is often a little shudder and the revs dip slightly, but then the car picks it back up to about 1050rpm and lets it die down to normal tick over again.
No worries. I have a few videos of it doing this actually, I should stitch them together and post that sometime.
2006 BMW E60 520d SE 6MT
2009 BMW E90-LCI 330d SE 6MT
Current: 2012 F30 328i Luxury 8AT
2015 Audi A6 Avant Ultra, Black Edition (sorry!)