Buick REGAL 1997 Manual page 64

If your child restraint has a top strap, it should be
anchored. If you need to have an anchor installed, you
can ask your Buick dealer to put it in for you. If
you
want to install an anchor yourself, your dealer can tell
you how to do it.
Canadian law requires that child restraints have a top
strap, and that the strap be anchored.
If your child restraint has a top strap, your dealer can
obtain a kit with anchor hardware and installation
instructions specifically designed for this vehicle. The
dealer can then install the anchor for you. In Canada,
this work will be done for you free of charge. Or, you
may install the anchor yourself using the instructions
provided in the kit.