Tesla's master plan part 2

A couple of weeks ago when Tesla announced its bit to takeover SolarCity, I noted down my suspicions that Tesla would introduce a solar powered electric car. A few days later Toyota announced it's new solar powered Prius, beating Tesla to it, although with a hybrid car. A few hours ago Elon Musk seemed to confirm my suspicions as he wrote on Twitter: "Working on Top Secret Tesla Masterplan, Part 2. Hoping to publish later this week." And 2 hours later: in a tweet in response to a blogpost about the reason for the SolarCity takeover: "Kinda. Creating a seamlessly integrated Tesla battery & solar power product that looks beautiful is the reason"
Bets are still on. I don't think it's a seamlessly integrated home system. I think it's going to be an integrated system on wheels.

Tesla + SolarCity = Solar electric vehicle

When Elon Musk announced Tesla's takeover bid for SolarCity he talked about synergy: using solar power to charge up your Powerwall home battery. And then using that electricity to charge your Tesla car. This deal has been criticized by many because there seems to be very little synergy between his car making business and selling rooftop solar panels.
When Tesla announced construction of its own Li-ion battery factory it made sense to people: you use the batteries in cars and you can sell the same batteries for storage at home. Now the thing is: it's no different with solar panels. It has already been shown that solar panels can be used to extend the range of electric vehicles. This bid is an indication that Tesla may be considering offering solar roofs on its cars.