Hi Willie- thanks for pointing the SF Bay Area climate piece of the equasion.... totally true....also, my car hasn't been regularly used in 100+ degree weather conditions- - so, my experience travelling to and from higher temp areas may not be too representative of living with one in such areas

fwiw- I may have one of the cooler running E500's

This weekend in Marin (80-90 degree ambient temps), I observed a bit higher operating temps (w/ ac on- two people in car) steady in the 90-95 degree range....also observed a trickle of coolant seeping around/from the overflow bottle cap

I r/r'd the cap yesterday and Happy Happy! She's back to running steady at 85 degrees on the gauge (75-80 degree South Bay ambient temps, a/c on, stop and go city traffic blasts)

Best regards
-fad