It consumes money from your account each month. Otherwise, I am not sure as I use it the same way you suggest, and let the trial period expire.
Some people have commented that the AT&T connection of the car might give you another chance at a signal where you might not get one if your phone is on Verizon or T-Mobile. Also, as a hot-spot for others in your care using an iPad, etc. You mentioned that your phone can do that, but I bet not many people want to take that step if they regularly have tablet users in the car. Or maybe they have a phone plan with limited data.Stupid question from a new owner: the Toyota app suggests for me to sign up for a Wi-Fi connect trial. So far, all I have been able to determine is that this would allow me to use the vehicle as a WiFi hotspot (which my iPhone can already do), and do "integrated streaming," (what is that?) - I already have an Apple Music subscription, plus the car provides Sirius satellite radio (if we decide to continue it after the trial period). I can already play music thru the car stereo using the iPhone and CarPlay. Can someone explain what other features or benefits this Wi-Fi Connect provides?