Maybe this has been mentioned already so forgive me if it has. Could Tesla be intentionally delaying some deliveries because they are skirting close to the ever so precious 200,000 car limit for the$7,500 tax incentive? The rebate phase out starts the 2 quarters AFTER the 200,000th car is sold. So for Tesla, it would be in their best interest to make sure that car 200,001 is sold after 1/1/18 and not before. Otherwise the phase out would start first thing 2018. If they hold up a few shipments they could secure another full qtr with the full $7500.
The caveat is that this only makes sense if they are close. They might not be, I have no idea.