Hi, in general is easy to find. Just try to find "volvo radio y cable". for example:
"aliexpress here" or "ebay here".

new firmware released:
V2017-08-02_1
Fixed
- Bluetooth: Audio gain control settings.
- Modem: Some updates regarding Paired device management.

More info here in changelog.

Good morning Marek,

I've completed an order form this morning. Are we still looking at March for shipping or do you now have more orders to fulfil?

Let me know how and when to send payment and how much shipping will be and I'll get payment sent.

I've ordered a splitter. It's a melbus splitter from volvotech which I think is the right one. It's a little more expensive than the eBay ones but I was ordering something else from them anyway so there's no additional shipping cost.

Looking forward to hearing from you.

small bugfix:
V2017-02-12_1
Fixed
- Modem: Paired list fix (Wavecom modems).

the new firmware brings new feature: it's possible to use microphone for the voice command. if the microphone is required the new incomming call named "Microphone" appears. after accept the call by green button you can speak ;) .
example (in czech) is here.
v2017-02-19_1
News
- Modem: It’s possible to use Car Microphone for voice commands.
Fixed
- Radio: Invalid status on the Radio display (in the SAT mode).
- Bluetooth: Some small updates.

You are a fantastic, beautiful human!

I've been waiting for something like this since buying my car with the antiquated phone and having to use a second SIM card with its own phone number...

I will gladly buy two units; do you have an updated lead time for availability?

Many thanks, you've really made my day!

On-Call
 

One potential issue; my phone module has the On-Call and SOS buttons, with a built in backup battery.

How will your Bluetooth module affect the operation of these features? I'm assuming that pressing one of the buttons will make a call to the On-Call operator via a Bletooth connected phone, and any features like remote car unlocking etc will not work... Is this correct?

What would the phone module have to do with remote unlocking of the car?

What ecto is talking about is the ability to have the car unlocked remotely without the remote.

A phone call to Volvo on Call, some verification and ping, your doors are unlocked.

Indeed; very handy if you manage to lock yourself out. The operator can also track your car via the built-in GPS if you forget where you've parked...

Neither of which is likely, but it does give me the warm & fuzzies knowing it can be done.