Apparently the vehicles specs are also narrated by the AI Cortana as she regales some stories about it. The Halo 4 iteration of the Warthog won't be driveable.
Halo 4 was announced at E3 this year and is being developed by Microsoft's internal 343 Industries studio. Forza Motorsport 4 releases on Xbox 360 October 11th. Check out the fancy new high definition design of the iconic Halo Warthog below.