The Nano from Tracker can be a very small self-contained device that can be fitted discreetly in the car, and operates otherwise with the others listed here. Monitoring the car’s area from the application or online portal is rather convoluted, Though after getting the cling of it, it's reasonably simple. https://www.trackerfit.co.uk/blog/rising-concerns-over-keyless-car-theft-devices-how-trackerfit-can-help/