Fellow car enthusiasts, what should be done if there is a paint smell when turning on the heater in a half-year-old car?

Try replacing the air conditioner filter, that's often the issue. Or you could try deodorizing the car interior.

The air conditioning filter needs to be replaced. If possible, buy a bottle of blower cleaner. Additionally, if you have a visual inspection tool, use it along with the cleaner to clean the evaporator fins.