Original Title of thread was "A question from a new owner" - thread title changed by Michael for archival purposes.
Do the objects you refer to look like what is in the first photo below?
If so, this is a guide fixture for mounting an ISOFIX (European nomenclature, means International Standards Organization - Fixture) or LATCH (North American nomenclature, means Lower Anchor Tether Child Seat) design child seat.
All passenger vehicles manufactured since about 1999 have been equipped with hooks in the rear outboard seating positions to allow an ISOFIX or LATCH child seat to be attached to the vehicle. The guide fixtures are provided by Volkswagen as a courtesy, and are supposed to serve two purposes: 1) Make it easier for the person installing the child seat to locate the mounting hooks, and 2) Protect the upholstery of the vehicle in the vicinity of the mounting hooks. The guide fixtures are not part of the ISOFIX or LATCH standard, but the little buttons that are attached to the base of the rear seatback, indicating the location of the mounting hooks, are part of the standard.
These guide fixtures work very well on all VW products except the Phaeton. I had an Volkswagen brand ISOFIX child seat (purchased in Switzerland) that I used occasionally in my 2002 Golf when I was transporting my 4 year old niece. I tried installing the guide fixtures on the Phaeton, and found that the seats of the Phaeton were too heavily upholstered to accept the guide fixtures without risk of damaging (deforming) the leather seat surfaces. The actual child seat will slide into the mounting hooks on the Phaeton without any difficulty, though.
My suggestion is that you use a normal (meaning, restrained by the seat belt) child seat only in a Phaeton.
Guide Fixture for ISOFIX / LATCH Child Seat mounting hook
Buttons on rear seat backrest identifying location of ISOFIX / LATCH Child Seat mounting hooks
ISOFIX / LATCH mounting hook
ISOFIX / LATCH mounting hook on Golf IV
Guide Fixture installed on ISOFIX / LATCH mounting hook (again, on a Golf IV, with thinly padded fabric seats)
diagram from owner manual explaining how to mount the guide fixture
The guide fixture is optional, the child seat will install and hook into place without the guide fixtures. They are not provided in Europe or Canada, only in the USA.