How come we got so far in this wonderful game, stepping up the realism further and further, having specific sound changes when changing exhausts, transmissions, tires whilst not having a change in sound when driving a Cabrio or removing the Targa roofs or removing doors in an Offroad vehicle or removing the windows for a sunny day experience? One has to fit a louder exhaust to make it seem somewhat realistic then. I am not talking about adding window buffeting effects and making window mechanisms or Cabrio versions of every car with convertible mechanisms. I just would like to drive with open windows and having the car be louder, the tire screeching intensified and suspension sounds more distinct.
It has been stated many times over and over again that the interior filter is hardcoded in game engine so this is not something the devs can just do easily without messing up a lot of other audio related things. They are definitely planning a better system but it could take years until they finish it.
In a state like that it also makes sense why there are basically no stock game cars with convertible versions... Because they know they can't be realistic or anything close.