I bought the key series version of the cable for my 04 fabia thinking that was all i needed but it tells me i have a can bus as well when checking the status.

So what are the differences between the k-line method and the can-bus system? Am i able to see all of the modules or can you only see some via each method?

Newer cars like the Octy II need can bus older ones K-line IIRC

Ross-Tech: VAG-COM: CAN-Bus Information

I Have tried to read all of Ross's site, that only talks about later platforms. But the status test tells me CAN interface works, and there is a CANBUS module detected when searching for all modules.

Tha Fabia (even the new model) uses always K-line for diagnostics, but it does have an internal CAN's for communication between the control modules. The CAN Gateway you found with your scan connects these CAN databus's and allows messages being send from one databus to the other one. Makes sense now?