V70 D5 Difference model year 2005 to 2004?

Hello, after now 16 years of golf gurking I want to finally switch to the league of the more pleasant driver’s office and love the Volvo V70 for a long time. Especially since I would like to offer my wife and my little daughter a maximum of possible safety. Not to mention the additional space (stowroom). And he looks chic also ;o) I have come across quite favorable offers in the range of the model years 2004-2005. One stands out, but this is the model year 2004. What has happened in the model year change to 2005 at the V70 D5, what would justify a “extra price” of good 1500-2000 euros (apart from age)? I am concerned with eliminated (material) weaknesses, which the 2004er had yet to succumb to, but the 2005er no more.. or the other way 😉 Or has safety done something? Was the DPF installed as standard from 2005 on? Questions about questions. With please answer.