Elon also mentioned several times that he is talking in today's dollars so more like $35,000 plus inflation. Although I have heard him say $30,000 plus inflation, so hopefully he just dropped the inflation part and started using $35,000 (as in $30,000 plus inflation).
I think there will be some tax credits left but not much. At the end of the year we will have 180,000 remaining; remember these credits are only for US sold vehicles. He said that the Model S production line can handle 40,000 units per year and 50,000 with a minimal investment of $25m - $50m.
Optimistic scenario for 2014 would be 30,000 units sold in US (including some Model X at end of year). That leaves us with 150,000 credits. In 2015 max capacity of Model S/X will be 100,000 units. Let's be very conservative that 50% of those are sold in US. Therefore in 2015 and 2016 you will use up 100,000 credits and we are left with about 50,000 credits to begin 2017.
The only way we run out of credits by Gen 3 is if Model S and especially X demand far exceeds anyone's most optimistic expectations. In this case Tesla would have to build additional assembly lines for these two cars. Another scenario is that Gen 3 gets postponed even further to 2017/2018. But Elon said he expects late 2016.
If we do run out of credits due to Model S/X demand exceeding expectations then I will not care one bit, because I will have more than made up the difference on stock price appreciation. Think of buying Tesla stock as a hedge against running out of tax credit if you are planning on buying Gen 3.
