GameSpy have posted up the second part of the SRS Developer Diary in which Design Manager, Kev Shaw talks about physics and game-world dynamics:
"The physics in SRS are as close to reality as possible -- objects have inertia, mass, and all that other stuff you didn't pay attention to when your science teacher was explaining it all. Thankfully, our programming team were paying attention, and as a result, they've created a game world that behaves in the same manner as the real world.
For example, tyres (or "tires" for our U.S. readers) are modelled based upon real-world data. This means that they behave in a lifelike manner, so push them too hard and they'll lose grip, heat 'em up and they become more effective (or "grippy"). The result is that players can "feel" when their tyres are about to "lose it" on a corner, for example, and either throttle off or attempt to correct the imminent spin off."