Porsche wasn’t included within the launch of Forza four attributable to complications with EA, who had the license at the time. however Porsche makes its come back to the Forza franchise nowadays (as promised) with the Porsche growth Pack DLC.
The Porsche growth Pack is accessible to download at once for 1600 MS Points ($20) in Forza four, and adds thirty new rides to the virtual garage and new Porsche events in World Tour and Rivals modes.
Source: Xbox.com
