Last week we reported on a mysterious Apple van making its way around San Francisco.

After writing about how the van could be used for a self-driving car, we got an unsolicited email from an employee at Apple about "vehicle development" at the company.

This person said Tesla employees were "jumping ship" to work at Apple.

"Apple's latest project is too exciting to pass up," the person said. "I think it will change the landscape and give Tesla a run for its money."

Apple has about 50 employees who previously worked at Tesla, according to LinkedIn. Many of those hires were engineers who interned at Tesla. Most of the engineers Apple has hired from Tesla specialize in mechanics, manufacturing, and robotics.

We can think of a couple of possibilities here. Apple may indeed be building some kind of vehicle, although this seems way outside the company's core.

More likely, Apple is working on new iPhone-to-car experiences that will compete with what Tesla offers in its vehicles. Apple has an initiative called CarPlay that lets you control certain cars' entertainment and other systems with your smartphone. It was supposed to come out in 2014 but has been delayed, and it has only just started to emerge on cars like the 2015 Hyundai Sonata.

So perhaps this Apple employee is talking about things like using your iPhone to unlock and drive a CarPlay-partner car without needing a key — Tesla began offering this with its 6.0 system update last year. Or perhaps a much deeper set of integrated experiences with navigation, audio, and other systems.

Whether or not Apple is working on a car of its own, the company seems to compete with Tesla for top talent.

Tesla has hired about 150 people from Apple so far, according to Bloomberg, and Apple has reportedly tried to appeal to potential Tesla hires with $250,000 signing bonuses and huge salary hikes.