Usually, when you pair your device to a car, the contacts download to the car's hard drive once and remain there. They do not download each time you connect your phone. This is why when you get rid of a car you should delete any paired phones from the car and make sure the data gets erased.
I haven't gotten a new car. It paired just fine this morning as usual. My phone took an update, and I began having a problem this afternoon. I came back out 2 hours later, and my phone paired no problem with the contacts . Must have been a glitch.
