There are very cheap units available on eBay that you just add a sim to & wire up in the bi,e or any other object you want tracked. The down side to GPS or Phone based units is the bad guys know how to defeat them & often will take them to a store where there is no phone or gps signal. But if they don’t and you are lucky & they don’t find and disable the tracker I hope your cops are better than ours, as even with a theft report & now an exact GPS location for where the bike is, we still have trouble getting the lazy sods to send a unit round to catch the bad guys & recover the property. They seem to think that insurance means they don’t have to bother !