Cars have had remote start systems since before the first cell phone was invented. What is LTE/4G/5G adding in this scenario? Who exactly needs to start their car from the other side of the world? It's trivial for manufacturers to add a short-range radio that will work from across the driveway, which is what 99% of their customers want. In fact every key fob already has this functionality, which is how cars can unlock from a distance. As the article states, Mazda themselves had this version of remote start until they removed it in favor of the subscription option.