Ask what opens
Clarify whether the roof is fixed glass, has an opening section or includes a separate blind. Do not infer operation from the size of the panel in a photograph. Ask the seller to describe each part and locate its controls.
Demonstrate with care
If conditions allow, have the seller operate the roof according to the vehicle's instructions. Keep people and objects clear of moving parts. Do not force a panel or continue operating it if movement is uneven, obstructed or accompanied by a warning.
Look without dismantling
Inspect visible trim, seals and surrounding interior surfaces for damage or marks. A mark is a reason to ask a question, not a diagnosis of its cause. Avoid pouring water over the roof or pushing objects into openings to perform an improvised leak test.
Make a practical decision
Check headroom from the seats you will use and assess whether the blind provides the comfort you want. Record whether the opening mechanism and blind were demonstrated, and note anything left untested. Ask about previous roof repairs if there is a concern. A roof specification describes equipment; questions about leakage, adjustment or mechanical condition belong in a proper inspection.