Sure enough, pulled out the middle knob and voila! The bulb resides in a socket at the 6 o'clock position.

Looks like I need surgical tweezers to remove it though, but the hose trick looks like it'll work as well.

Only one bulb...a large plastic bezel allows the bulb to illuminate the rear of the adjacent knob displays...

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car