The Mercedes-Benz of Christmas light strands would be a set that had a bulb-out indicator at the plug socket...and you would be shopping everywhere looking for OSRAM-type bulbs to replace the burned-out ones...

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2009 ML350 (44K) - Weekend college shuttle
2001 CLK430 Cabriolet (71K) - Wife's car
2001 BMW 325CI (140K) - My daily driver
1998 Mustang GT Convertible (146K) - Daughter's car