The new rules are based on "final transaction value". Iirc include dealer fees, accessories, and add-on packages, but as well as discounts and incentives.
Excludes tax, extended warranty, and freight and PDI, etc (this was new to me, didn't realize that part!)
Full list of exclusions and inclusions here:
https://tc.canada.ca/en/road-transpo...-program#toc_2