As the title says, I’m looking for a reliable source for production number per models, trims, years...

Goodcarbadcars.com is usually pretty accurate, but they don’t go far back enough.

Specifically, I’m looking at the number for the 2003 Mitsubishi Eclipse GTS.

Yes, they are horrible vehicle, but I need the number to prove a point.
(I’m so sorry you had to look at this car)