The next time you click on the lights and the "bulb out" indicator lights up, take a moment to check out what bulb is dark. It may be dirty contacts, or it may be worn insulation or wire creating an occasional fault. I've got an infrequent bit of that with the right front parking light that I need to fix.
Don't know where your temp sensor is, but I'd be willing to guess it's up front (mine's behind where the front license plate would sit) and part of a wiring loom that also contains a front parking or headlamp run, with wear creating an occasional fault.
'97 SL500, 40th anniversary edition
'04 Olds Bravada (SWMBO's)
'06 Lexus ES330
'89 560SL (sold)
SL--Anything else is just a Mercedes.
(Kudos to whoever said it first)