Nancy, you are right that it used to be this way, but it changed in 1992.
Here's the note from the record in LC's online catalog:

Notes:   SERBIB/SERLOC merged record
          The Dec. issue is the annual Buying guide issue for the following
year, <1944>-92; this issue is one of two published in Dec. and designated no.
13 within each vol., 1993-97. Buying guide for 1998-    continues to come with
subscription to Consumer reports, but no longer bears its volume and issue
numbers.

Hope this helps,
Elaine Donnelly, Librarian/Technical Services and Digest subscriber
National Geographic Society Library (109.267-241)
1145 17th Street NW, Washington DC  20036-4688
202-857-7794 voice ; 202-429-5731 fax
edonnell@ngs.org

>>> crowna@QUINCY.EDU 11/14/02 08:54AM >>>
We just received Consumer Reports v. 67, No. 12 Dec. 2002.  This is a
separate issue which says "The Gift Guide" on the front.  It is my
understanding that the December issue is always the Buying Guide for the
year.  Many libraries catalog this separately as a monograph.
Has Consumer Reports changed this?