I haven't been able to find an online calculator that quickly and simply calculates all the taxes, duty and fees that apply when you bring a car across the border -- so I build a really basic one myself and posted it here:
http://importacartocanada.comAll you need to do is enter in the US purchase price (in USD) and it does most of the work for you, including using the current exchange rate.
It has a few quirks because of my technical ignorance and the limitations of the Zoho spreadsheet I used (primarily that it doesn't support drop-down menus in a cell). You need to enter 'Yes' or 'No' manually into the 'Made in NAFTA Country' field, and to change the Province you need to specify the cell you want it to use. For example, if you are in Ontario, enter:
=E6
into the Province field (that will ensure it calculates the sales tax correctly).
The 'Recall Clearance Letter' fee is something specific to BMW, so enter $0 or whatever amount your manufacturer of choice charges. And the 'Inspection' is an estimate of the BC vehicle inspection fees.
I'm going to make a proper JavaScript calculator that will do all of this work for you, but for now, enjoy!