Final assembly in the United States is a yes or no test for the car loan deduction, and the badge on the trunk does not answer it. Two sources do.
Route 1: the Monroney label
Every new car carries the factory window sticker, the Monroney label, and its parts-content section states the final assembly point: the city, state and country where the vehicle was put together. If you still have the sticker, or the dealer can reprint it, that line is your answer.
Route 2: the NHTSA VIN decoder
Enter the VIN in the National Highway Traffic Safety Administration’s VIN decoder. The result includes the plant of manufacture and its country. US final assembly there means the test is passed, subject to the other qualification rules.
The quick first-character signal
The first character of a VIN is a country code: 1, 4 or 5 mean the United States, 2 is Canada, 3 is Mexico, J is Japan, K is Korea and W is Germany. Take a fictional VIN, 1HGCM82633A004352: the leading 1 points to US assembly, so this car passes the first-character screen and the decoder or label would confirm the plant. A VIN starting with 3 would fail the test however American the brand sounds. The car loan checker runs this screen on any VIN you paste, and treats it as a screen, not the final word: confirm with the label or the decoder before you rely on it.