[epoyn]

The airbags seem to be an option for the US as well according to the CLA US Ordering Guide.

I am curious to why there is little information about the 4Matic system.

This is all I could find about the 4Matic system and it is regarding the A45 AMG model rather.

Despite being a front-wheel drive-based car, Mercedes says the A45 will be able to route more power to the rear wheels. That paired with the brand’s “Curve Dynamic Assist,” which slows the inside wheels slightly in a corner for improved handling, could mitigate common front-drive handling complaints.