Lets start with the most important one "squirrels"
As you race along the California Coastline expect to see the odd squirrel dart across the road.
Each car has 30 different impact zones, metal will bend according to real-life crash test data and every part of the car that falls off will remain in the game world as a physics object.
Every CPU-controlled car you encounter will be driving with three personality traits taken from a pool of 80. Some will strive for fast lap times but avoid contact with other racers at all costs.Others will refuse to yield if they’re in the process of being passed. And the occasional driver will seek revenge if you bump them off the road.
All assists have been removed from the game aside from optional automatic gears.
Corner-cutters will find their cars have less power and they’ll be hampered by this lower performance until the advantage they gained has been cancelled out. Similarly, racers who enjoy a bit of the old argy-bargy will find themselves racing against similarly aggressive drivers thanks to the new matchmaking system, while those wishing to race like gentlemen should find themselves with like-minded people after the two parties get separated.
The physics engine is running at 1,000hz, which means the car tyres’ contact with the road surface is simulated a thousand times a second (even taking into account tyre bulge and morphing of the tread as you corner).
All of the grid spots (12 in total) can be occupied by human drivers over the internet, with any spots not taken up by real people filled in by CPU racers instead, meaning the race will never feel empty.
Thanks to Gamesradar for most of the info