just thought about this and i was about to agree with you, but look at another angle...

these are track cars... like race cars in a sense... everything about them is designed with one thing in mind... making a car go faster round a racetrack. adding bits n peices like trackers and alarms n stuff have no purpose on a racetrck, and will afect performance (however minimal) due to weight etc. etc. (even tho having a shit before getting in will probably lose more weight... lol)

so the focus/emphasis on keeping the cars secure must be aimed at the physical security of keeping the theives away from the cars to start with...

ie garages with decent locks etc. etc (ie im sure the sierras kept ina pretty secure garage most of the time)

when taking it to anywhere outside you have to rely on the security in place... or stay with the car... so if the car's left somewhere overnight (be it at donno or in a garage like say MSD's unit etc.) then you have to trust the security inplace of stopping people getting into that place...

unfortunately in the case of donno the security was a joke (based on what ive heard!)