With many modern cars, especially luxury ones, they come with a way to put a sim in it, so that they can provide you with ways to locate your own car (to remember where you parked), provide a wifi hotspot, integrate google maps, among other things.
Also GPS doesn't work so great when you're parked in a multistorey carpark, which is probably the only situation where I might forget where the car is parked.
I do realise that it may have other advantages, the wifi hotspot and google maps being good ones.