Main question underlined below. I'm wondering if anyone can comment on the inter-compatibility of the 86100-YY050 extension modules that are available for the Prius and other Toyota cars/trucks. For reference I have a 2012 Prius v with non-JBL stereo that until last week also had nav and Bluetooth audio. My stereo model is 57015 (with HD and XM), which google does not seem to know much about. Seems like the same as 57011 . Could this be a Canadian model? As documented in other posts, I have the common loss of NAV, Bluetooth and APPS functions but the AM/FM/SAT radio still works. From what I have seen on these forums and Reddit, this is due to an extension box failure or the harness that joins the radio to the extension box. Because I have a black screen instead of a "Function not available" message, I do not think it is just the harness. I have seen some comments that relate this failure to over use of the USB charging port but have not been able to confirm such a thing. Anyone else heard this? The number 86100-YY050 is printed on the extension box on photos of similar extension boxes/modules I have seen on Ebay, in forums and on Toyota parts websites. However there are different PT numbers (PT296-47130, PT296-47140, PT296-47140AA, PT296-47140AB, PT296-47141) . i have yet to pull mine so cannot say yet what it is. Does anyone know whether these parts might be interchangeable or definitely not interchangeable without also changing the head unit? Is there one that is less likely to fail again or better in any way? If a person searches the US Toyota parts website for PT296-47140, it seems to indicate that the *40 box replaces the *20 and *30, but this is not a really clear statement. This also doesn't speak to the AA and AB versions. (I tried to include link but don't have status yet.) Is there a current part number that is compatible and comes at a reasonable cost? For anyone coming across this post without having read the other posts about this issue, the extension module is bolted below the main head unit and is removed with the main head unit. It is manufactured by Harman Automotive and is sometimes call the Gracenote Extension Box, Extension Module or Bluetooth module. It is responsible for the Nav, Bluetooth audio and Apps functions. A search for pictures of 86100-YY050 should show you what you are looking for. According to older posts, this box was once an $85 item and now is 10x that from the dealer.