Highway Wars is a new mode which sounds a bit like the Track Days feature in Forza 4, but with a healthy dose of Red Bull pumped in. 

In this mode (which is a mixture of the battles from NFS: Undercover and pedal-to-the-metal racing), players must race weave through traffic at high-speeds against AI racers. 

Perhaps the coolest feature of the Challenge Series is one that is aimed at NFS veterans. There will be locations based on old NFS locations, such courses from NFS: Carbon, Most Wanted, and Underground. 

By completing this series, players will unlock the Mazda RX-7 (finish the first 30 events), the Porsche 911 GT2 (complete all 60 of the Challenge Series events), and the Corvette Z06 (dominate at least 31 events). 

SOURCE | GAMING EXAMINER