Forza Horizon 2 DLC pass owners get the DLC free, while everyone else must pay $5 for it. However, you don't need to pay anything for the 2010 Mazda Mazdaspeed 3 car, which is available as a free download for all Forza Horizon 2 players during January.
For more on the cars included with the Forza Horizon 2 G-Shock Car Pack, see the list below, as well as the image gallery at the bottom of this post.
Forza Horizon 2's G-Shock Car Pack Includes:
2015 Nissan IDx NISMO
1980 Subaru BRAT GL
2013 Ford F-150 SVT Raptor Shelby
1975 Ford Bronco
1953 Ferrari 500 Mondial
January's Free Car For All Forza Horizon 2 Players: