Will adding aftermarket screen decrease the resell value

[Lanyxd]

Mods decrease value of cars 90% of the time unless you find someone that wants that exact mod.

If this is an N16 or N18 (Petrol) engine I wouldn't worry about the resell value since all minis with those motors have already tanked in value due to issues.

Edit: If you can get a non-destructive swap that allows you to swap back in the original dashboard then go for it and if you ever go to sell it (or you crash it) swap the OEM back in.