How is the rear quarter panel supposed to be attached to the wheel well?

[jsuen]

Long story short - my mechanic told me that the car previously had rear end damage and noted that the rear quarter panels should be welded to the wheel well/structure of the car because it is a uni-body. He said the rear quarter panel is just glued to the wheel well. I took the car to a reputable body shop and they said that it is fine and there isn't a need to spend extra money welding the quarter panels to the car.

Since I'm getting conflicting information, I want to see if anyone here knows how the rear quarter panel is supposed to attached to the car and whether or not I should be worried about the car's structural integrity? I'm planning to keep this car for a very long time and want to fix things right.

Thanks!

[bmwfnatic]

Take a picture?

Both the outer rear arch (quarter panel) and the inner rear arch have a U-shaped channel where they overlap, these two are connected together by a series of spot welds.

[liam821]

If I recall, it's held together with spot welds and seam sealer.

[jsuen]

The car is current in the shop so I can't take pictures of it right now. The U channel rings a bell - I remember my mechanic telling me that the "tabs" were shaved off. How important is this attachment point for car's structural integrity?