mercedes/r-class/2006-2012

Oil pan

I have a 2006 R350. Oil light came on....put in a few quarts of oil got back on the road, it appears that oil may be leaking (smoky - thought it was just oil that may have spilled), however saw it on the road after pulling over. How do I know if it is the oil pan that is leaking or something else?
Do you have a pic of the underside of the car?
Traveling, no access to car lift.

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