This is one from a different tangent...have you engaged your emergency brake recently? Or at least had the clicking happen thereafter?

I had to get my e-brake adjusted when I discovered a rhythimic clicking as you experienced. In my case, it happened in forward and reverse.

Also in my case, I have aftermarket rims and the lug bolts that came with them were a bit long and interfered with something in the hub.

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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