CCC Information Services, Inc. v. Maclean Hunter Market Reports, Inc.

44 F.3d 61 (2d Cir. 1994), cert. denied, 516 U.S. 817 (1995)

The Automobile Redbook is still available in both print form and online, though it is no longer published under the Maclean Hunter brand.

As a side note, in its opinion the court made a small mistake with regards to other car valuation publications. The NADA Official Used Car Guide, is not known as the "Bluebook," that distinction belongs to the Kelley Blue Book.

And, in case you need further advice on your car's worth, you can turn here or here.