For those who don't know NetKar Pro I can say that it is one of the best driving simulators on the market. The force feedback is great and the physics model is extremely accurate.
In this free release you can drive the 500 Abarth Assetto Corse, a small track car with 200 Bhp and a peak torque 300 Nm at 3000 rpm, on all the NetKar Pro tracks, including the new relased track of Aosta.
If you are wondering how much the driving model is realistic consider that NKP's 500 abarth has received the "Simulation car of all time" award fom the online magazine Inside Simracing
While it is possible to drive using the keyboard or a pad the best experience is obtained driving with a (good) wheel.
You can download it here
If you are interested to the full version of NetKar Pro please refer to the official site (where you can download a demo of another netkar pro car, the F1000)

Sorry, I'm a diehard rFactor person and I will fight anyone who challenges me.

I suggest you to give it a try, while the multi is less solid than rf the FF and the physical model is on the same level if not better than gMotor based games