Make Sure There's a Customs Office on the Field
If you already know the drill, I apologize. If not, you'll need to file an electronic EAPIS form prior to departing Canada. Also, in spite of your ETA being on this form, you'll need to CALL the customs office at your destination prior to departure. Make sure you'll be arriving during the custom office normal hours. Anything outside of that will incur a healthy fee to bring in two officers "after hours". I believe even KDTW has an extra fee after midnight. Leave extra time to process thru. On a trip this month from Montreal to Michigan, it took over an hour for two guys to process me (no passengers or goods). My experience on your side of the border is generally much better.
Terry, CFI
RV-9A N323TP