The "SWP: Aux Battery Supply Low" ID: 428 message popped up on my VDS over the weekend. I found that pretty impressive considering I live in a desert and I've been on the same battery as when I bought the car as a CPO in 8/2013. Anyway, I'm about due for annual service so I just scheduled it all together. Annual Service: $600 Auxiliary Battery: $250 That battery replacement costs seems a bit much. I complained, but my regular service advisor is out on paternity leave, and all the new faces didn't seem to care that much. Does this $250 12V replacement seem right to others. The price was handwritten on my service invoice and I got the sense they were just winging it.