If the car doesn't have roof rails and there are no fixed points left by the manufacturer, then only clamp-type roof racks can be used. The fixation of clamp-type racks is actually lacking because the clamping force of the rack is limited. When placing heavy items like ladders or wood on the rack, braking or turning the car might cause the base of the rack to move or even slip off the roof. Our current solution is to drill holes in the roof and use rivets to secure the base of the roof rack to the roof, making the roof rack much more secure.

1. **Limited clamping force**: Clamp-type roof racks have limited clamping force, which may result in base movement or slipping when the vehicle is in motion or turning.

Solution: Add additional fixing measures, such as using specially designed reinforcement accessories or additional support structures, to increase stability and safety.

2. **Risk of damage to the roof**: Using clamp-type roof racks may exert pressure or scratches on the roof surface, especially when used for extended periods or carrying heavy loads.

Solution: Use pads or protective cushions on the roof to reduce direct contact with the roof, and regularly inspect the roof to ensure no damage has occurred.

3. **Not suitable for all vehicle types**: Some vehicles may lack structures or designs suitable for clamp-type roof racks, requiring the search for other types of roof racks.

Solution: Before purchasing a roof rack, carefully check the vehicle manufacturer's guidelines to ensure the chosen roof rack is compatible with the vehicle and meets safety requirements.

The solution you mentioned—drilling holes in the roof and using rivets to secure the base of the roof rack to the roof—can indeed increase stability, but it needs to be done properly to avoid damage to the vehicle structure and may affect the vehicle's warranty terms. Before making such modifications, be sure to consult with professionals or the vehicle manufacturer.

Roof top tents should NOT be placed on top of Clamp Mounted crossbar systems without rivet attach to the vehicle roof