What would be the most economical plan that only is needed for low usage data, with voice and text unnecessary. It is intended to be left in a vehicle for use only as a Waze (GPS) device, attached to Android Auto.
According to prepaid compare - cheapest data plans with unlimited slow data are $5:TMobile Broadband and Tello both with 500MB of fast data Hello Mobile is also listed, but I'm not certain that plan has unlimited slow date. If you know you data need and can work with capped data and/or you need something besides TMobile network, then you can try the redpocket plan for 2.50/mo for 200 mb or try a tracfone annual plan with 3 GB (~250MB/mo). If you data usage will vary month to month, the tracfone annual plan may work best for you.