Bluetooth
As far as the puck goes, get one on eBay. I bought mine for $90 ,and there are a ton for sale at any given time. $537 might have made sense when these were new cars, but I'm surprised the dealership would still be charging that much
$140. I haven't searched E-Bay yet. Are they all compatible?
If it's the Bluetooth module in the arm rest, there are 3 options -
MB HFP which is the most common one. Cheap on Ebay but try to get a more recent model
MB SAP which is more expensive and has more features though it's incompatible with a lot of phone
Aftermarket Viseeo models which has a lot more features and cheaper but I'm not sure about the quality


