Here is some info from IGN:
Need for Speed Underground takes the acclaimed franchise to the "world of high performance street racing." The title, which is faster than ever, features 20 fully customizable licensed cars including beauties from Mitsubishi Motors, Subaru, Toyota, and more.
A customize element enables players to earn cash in races to pay for upgraded body kits and a wide selection of car mods and parts to create their perfect ride. The selection includes parts from provides like AEM, Audiobahn, Bilstein, Dazz Motorsport, DC Sports, Eibach, Enkei, GReddy Performance Products, HKS, Holley, Injen, Jackson Racing, MOMO, Neuspeed, Nitrous Espress, OZ. s.P.a., PIAA, Skunk2 Racing, Sparco, SteretGlow and Turbonetics.
Gamers will be able to drag race in a variety of gritty nighttime environments and advance by putting everything on the line, including their reputation, and then winning.
It seems there are a few racing games at the moment using this street racing format, we will have to see if this one can compete with the likes of Midnight Club 2 which has an online mode. It is due out early next year so we will find out later about online play.
Link here