ive had this issue since I started learning to mod, even if i unpack a car and load it straight into kseditor then save as kn5 some of the pices of the car get shaded weird? like the dashboard is a lighter grey and the door is a bright white. Ive asked in a lot of discords and someone helped me figure out it was only on certain versions of CM and it seems to be a AO map issue? i recalculated the AO for the dash and it fixed the dash but broke all the other objects with the same material
https://imgur.com/a/8A4qY2y
https://imgur.com/a/8A4qY2y