SUCCESSFUL IMPORT
I bought a TMPS from Amazon, had it "installed" by my local Hyundai service center and received an invoice.
The officer at the Sarnia border looked at our documents and said we had everything needed, he filled out the 3 forms, we paid the duty, and he gave us the clearance paperwork. The officer did not even go out to look at the vehicle or the TPMS. We were on our way in less than 20 minutes.
***I don't think he cared to check the TPMS because the invoice was from Hyundai itself.