HERE is what it contains... Source

McLaren F1 GTR – The McLaren F1 GTR wrote itself into the history books as the only GT car to ever win Le Mans and is considered one of the finest examples of automotive engineering in history.

TVR Cerbera Speed 12 – The TVR 12 smashes past 60 MPH in just under 3 seconds. Production models were planned, but they were considered too powerful to sell to the general public.

Mitsubishi Lancer Evolution X – For over a decade the Evo has been billed as a supercar slayer – now the Evo-X in GRID lets you unleash its sledgehammer aggression in the Pro-Tuned class.

Honda S2000 – This roadster is heavily modified for drifting and has become a cult-favourite thanks to its award winning engine.

Nissan GT-R (S-G2008) – The production model was Top Gear's Supercar of the Year 2007. Now one of the world's hottest cars makes its debut in Race Driver: GRID in its fully tuned racing spec.

VW Nardo – This powerful concept car made real from VW uses its 600BHP engine to rocket to 60MPH in 3.1 seconds.
Pontiac Firebird Trans AM – The 1971 racing edition of this true American legend is a worthy addition to GRID's exclusive group of muscle cars.

Volvo C30 – Adding to Race Driver: GRID's touring car roster

I read that the Aussie V8 cars and tracks will be avaliable for DLC.

quote Back2TheOldSkool

Anyone know when this will be released?

Just had a look on the grid website and couldnt see anything saying about the release date so .. im not sure ,

On the uk store theres some DLC for grid now .. to bad i dont have RaceDriver Gird anymore.

I still do and have bought it, Saw that it Says 1st of 3 cant wait to see whats next maybe new Tracks.