I love my BMW Airflow jacket but there are times where it flows too well an I get cold. I was shelping an extra jacket but hit on another solution. Picked up another brands jacket liners and viola! Climate control and not too much bulk. Smarter people probably already thought of this but I reckon there's other folks out there as challenged as I.
I found the liners by purchasing a complete jacket used so it was economical as well.
I find my FrogToggs rain jacket does fine over my mesh jacket on chilly 4:30 AM mornings. It packs small and is always on the bike anyway.
In most but not recent BMW brochures including the Airflow suit, the two-piece rainsuit appears on the same page. It's the intended airflow stopper.
FWIW, the new red top/gray pants set is a significant improvement over the previous black versions ... either of which blow froggs toggs away any day.
My jacket's large enough for Gerbing liner underneath and with that and the rainsuit on I've ridden comfortably when there's snow around.