I think you are being overcharged.
1,521,000 / 1.125 = 1,352,000 (Cost)
1,352,000 x 2.5% = 33,800 (FED)
33,800 x 12.5% = 4,225 (Incremental GST on FED)
You should ideally end up paying = 33,800 + 4225 = 38,025 (No any other tax)
Ask your dealer how come it is 45K?