What’s the difference between car manufacture date vs model year Ford Mustang?

[v8ismyheart]

This one confused me for a while—does anyone else get tripped up between the manufacture date and the model year? My 2020 Mustang was apparently manufactured in 2019, but it's a 2020 model. What's up with that? Does it affect things like resale value or parts compatibility? I just want to make sure I’m not missing something obvious here.