Buick 2015 Regal Owner's Manual page 54

Dirt and debris may collect on the
sunroof seal or in the track. This
could cause an issue with sunroof
operation or noise. It could also plug
the water drainage system.
Periodically open the sunroof and
remove any obstacles or loose
debris. Wipe the sunroof seal and
roof sealing area using a clean
cloth, mild soap, and water. Do not
remove grease from the sunroof.
Sunshade
The sunshade is manually operated.
Close or open the sunshade by
sliding. When the sunroof is
opened, the sunshade is
always open.
Safety Function
If the sunroof has any resistance
during automatic closing, it will
immediately stop and reverse.
To override the safety function,
press and hold the close sunroof
switch. The sunroof closes without
the safety function. To stop the
movement, release the switch.
Keys, Doors, and Windows 2-23