I’m planning to put 40k down and finance the rest. Do they finance the hst? Also when the rebate arrives can you simply pay off a chunk of the principal saving interest or is the interest precalculated?

Right but is the loan a set amount including interest or more like a mortgage where lump sums save interest?

Lump sums should go directly to the principle. Only the loan itself would contain interest payments. You could also take a small 14000 line of credit loan and pay that once the rebate comes in. That's what I'm doing. HST is paid up front. Mixed in with your down payment and loan.

As you make those lump sum payments does the original monthly payment reduce accordingly? Basically if I finance 30k and have my original payment for that, and two months later i pay off half of it, does the payment reduce to what a 15k loan would have been? Sorry for the questions. I’ve never financed a car before this one.

I must be missing something, what's the advantage of taking out a line of credit and using that to pay some of the car instead of financing the entire lump sum?

Yes but it's only for a 2 month borrow. If you have larger monthly payments over the length of the financing...the interest associated with those payments will be significantly higher. It's like assuming you're adding $14,000 as a larger down payment. (but really you're borrowing it for 2 months until the rebate comes In)

Ok, I see what you're getting at now. Sadly there's no rebate for us Nova Scotians, we are lucky enough to pay full ticket price!