Question Crossbars for external trunk

[enyworp]

Hello,

Through this topic, I would like to know what types of transverse bars I could install on my car (A4 avant model 2000 without longitudinal bars). is there a certain place marked on the car for mounting these bars? What do you think about the transverse bars with attachment under the outer frame of the doors?

I am waiting for opinions from users about this.

Thanks