I still think it has something to do with batteries/electronics. A few years ago I remember reading something about Apple wanting to use Tesla for the battery tech when Tesla builds their new $1 billion battery factory.
I wouldn't leave Tesla either for some "experimental" Apple project that may end up just being another "hobby". If Apple is failing to recruit Tesla employees it's because those people don't want to leave a good thing for something that may fail.
I find it hard to believe Apple is going into the mini-van business. Soccer moms everywhere will be so disappointed. I think Apple is more interested in hiring them for battery technology since the Apple Watch won't even last 24 hours.