My Alarm system has Remote start and Turbo Timer capabilites along with loads of other gadgetery such as Anti Hijack and Remote Shutdown
With my remote start engine will switch on but ALL doors will remain locked. If someone attempts the break into the car the engine will cut off AND the car will immobilise itself + set off the alarm.
Even if somehow they manage to get into the car when the naughty person releases the handbrake or presses the brake the engine will cut and immobilise + set off the alarm.
To drive the car after a remote start, the doors must be opened via remote and the key must be inserted into the ignition and switched to the on position.
On some alarms you can even add a code which can be entered via presses of the pedals to be able to drive the car.
With my cars alarms turbo timer, when the car is switched off the engine remains running. You can then leave the car and lock it via the remote and the engine will remain running until the preset time of the turbo timer. Once the timer has reached it preset the engine will cut and the car will be immobilised.
During the time the engine is running and the doors have been locked if anyone attempts to enter the car the engine will cut, immobilise and set off the alarm.
In all scenarios, if you are away from the car you will be notified via pager if you are withing range of the vehicle.
If I were incharge I'd say my alarm was CAT Best!