Battery appears to have run its lifespan after 4 yrs. When start/stop occurs, car complains of "power steering assistance temporarily reduced". Once car starts, issue disappears.
Called the dealer and they want $265 for the support (start/stop) or auxillary battery, and $640 for the main battery.
I can find OEMs of the main battery, but cannot for the life of me find a replacement / alternative support battery. What do people do around here?