I have been welcomed at the airport when arriving and could have driven the car to test before we started the process of purchase.
Everything was clear, as expected: with a lot of snapshots online, there was no surprise at the garage.
They have prepared all the papers to be able to take the ferry the same day. Although I couldn't drive back with both keys (as unavailable before driving in the ferry), they send the second key afterwards so that I received it a few days after.
Even though the first contact was not easy for a foreign customer as very few of the team is speaking English, everything goes well with the help of a Spanish-speaking friend and Toni who speaks English very well.
All the team was professional and comprehensive, I recommend.