Ordered 2 of these today. $30/plane.
https://www.binkgo.com/products/magnetic-mini-gps-tracker
I'll post a followup once it arrives. I'll follow my wife's car around town 😀(with her permission of course)
The product page is not very clear. It states GSM which would mean you would need to get a sim card from your cell phone provider and possibly pay monthly. HIGHLY discounted SIM cards can be bought from security providers since they are used as backups to internet connected home security systems and only transmit a small keep alive heartbeat.