[jwestfield]

You need to bring your laptop into the car. Try connecting to the hotspot.

Once you do, open your browser. It will send you to an att sign up page.

You will then be able to initiate the three month trial and set up a tie- in, if you wish, with your other att cellular account.

For some reason, you can't use your iPhone or iPad to do the initial setup.

After initial set up using a laptop as described above, you can then use any device including iPhone etc to connect to the hotspot.