Try ARS24.com, go to support and enter the radio and vehicle type. Which radio was previously installed also plays a role. They are very knowledgeable and will be happy to advise you competently. Although it's a German shop and costs a bit of duty, they deliver very reliably and you're sure to get the right one.

Search your vehicle exact type and buy subaru to iso adapter

You have to check with the garage, I have a Nissan and I had to fit an adaptor.