This is a complicated question!
My view is that the Aussie dollar will go down to 65 in the next year or so for a few reasons:
1. economic volatility will drive investors to safer currencies like the USD
2. mining boom continued slowdown, with countries less receptive to our coal and iron ore, means downward economic growth
3. interest rates will be further lowered to try and prop up business investment and housing investment, further driving down the dollar
4. lowered AUD drives local stock market growth, which many people want
All of this does three things:
1. Helps our exporters, which traditionally has been a very good thing, though I question for our fossil fuels sector, whether that's a good thing
2. Encourages foreign investment, which is a good and bad thing: it makes it more attractive to invest in Australian projects like utility scale renewable energy projects; but at the same time fuels property prices growth for foreign investors
3. Makes it harder, much harder in fact, to import things, like the Model X
That's just my take. I would say that if you're looking to buy a car, do it now, and be happy. Tesla have, what I presume, to be 3-6 month global currency hedges, so their movements aren't with the spot rate, but when it does move, it can move a lot.
I'm not a financial expert please don't use my advice for investment or purchase purposes, that would be highly ridiculously bad.