I have a manual 2009 C300 with DRLs activated for Canadian use. In brutally low temps I like to let it idle briefly while I brush my teeth before driving off. Unfortunately, all the lights remain on (for 3 minutes), then the parking lights alone continue to stay lit. My paranoid side is anxious about drawing attention to an idling vehicle. Does an idling C300 with DRLs not activated (as in the US) have any lights on?

No.

Assuming you have two keys and lock the doors when idling.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

not sure if it will help, but I believe most cars in the US with DRLs bypass them going on right away if the emergency/parking brake in on when the car is started. They remain off until you release the parking brake

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1994 E320, 145,000 miles

Thanks for the info gents. I'll see if a set parking brake eliminates the problem first then, if not, tackle it differently.