What is the Front/Rear Curtain Airbags of BMW X4?

No, BMW X4 isn't available in Speakers.

Here are the Front Brakes and variants of BMW X4:

Yes, BMW X4 has Front/Rear Curtain Airbags, which are: 2018 BMW X4 xDrive28i M Sport.

Here are the Cupholders and variants of BMW X4:

Here are the Rpm at Max torque and variants of BMW X4:

No, BMW X4 doesn't have Screen Size（inch).

Here are the Auto Headlamps and variants of BMW X4:

Here are the Capacity (L) and variants of BMW X4:

Yes, BMW X4 is available in Rear Air-con. The available Rear Air-con variants are: 2018 BMW X4 xDrive28i M Sport.