Apple’s latest mapping software contains six images dedicated to the parked car location feature, each a purple pin with a car-shaped glyph. It’s very likely that this is one of the many features cut from what is now the first public beta of iOS 8 late in development.
I think Apple has a lot more hidden and cutout features from the iOS 8 beta than these new features in Apple Maps. Maybe like the rumored multi window feature for example. They usually don't show us everything during the WWDC keynote.