Vehicle/Drone Stats, Devices on the Matrix Options

[Freejack]

Given that a drone (for instance) is a device on the Matrix, it should have a System/Signal/Firewall/Response. I'm having a bit of a problem trying to find out where these stats are derived.

The reason for the question is that the example characters, Drone Rigger and Smuggler both have vehicles and drones (with Pilot instead of System) with assigned numbers.

If I check out the Sample Device Ratings table, the drones should be a 3 and the vehicle a 4. But in addition, this also seems to imply that vehicles can have specific hardware and OS's installed and that they can be hacked to improve ratings just like a commlink.

As a rigger, I'd expect to find forums on Ares hardware and OS with details on how it interfaces and possibly hacks on how to improve the devices, similarly to hackers and commlinks with hardware modules and OS patching.

This is just my attempt to get my head wrapped around the provided rules. The main question though is as above. Where do the stats listed in the example characters come from?

Thanks.

Carl