In order to determine whether Fischer Fahrrad's 'TopLine' roof bars, model with product ID 126005, are compatible with your 2017 Peugeot 3008 GT 2.0, you need to check some specific information:

1. Vehicle Compatibility: Make sure the bars are designed for the roof of your Peugeot 3008. Roof bars are often specific to the type of roof of the vehicle (e.g. smooth roof, roof with rails, etc.).

2. Dimensions and Load Capacity: Check the dimensions of the bars and their load capacity to ensure that they are suitable for your intended use.

3. Fixing System: Check if the bars use a fixing system compatible with the rails or anchor points on the roof of your Peugeot.

4. Certifications and Safety: Ensure that the bars are certified according to European safety standards (e.g. TÜV) to guarantee safety during use.

If you do not have access to this information, you should contact Fischer Fahrrad directly or an authorised dealer to confirm the compatibility of the product with your vehicle.