Pairing Apple Watch 7 cellular with an automobile

I just bought an Apple Watch Series 7 with cellular capability so that I don't have to bring my phone with me all the time. I tried to pair it with my two cars and neither one will allow a connection. The Apple suppport personnel have informed me that the Apple watch won't pair with your car; only the iPhone, iPad and iPod devices will pair with your automobile.

So let me get this straight: I have just purchased an $800.00 watch which can test for heart arrhythmia, measure blood oxygen levels, heartbeat and calories burned. It will accept phone calls and I can make phone calls - but I can't do it through my car while driving?

"No sir, but you can always bring your phone with you if you want that capability from your car."

I am paying an additional $10.00 per month for cellular capability to the watch - but I can't do the simplest of tasks - which is to pair a simple bluetooth connection with my car in order to take calls - with a device that obviously has the horsepower to do this. Why do I need cellular capability if I need to bring my phone with me anyway?

Somebody please tell me this is incorrect information. I can't believe this is where Apple is drawing the line.