Hy @hmattoo
The wind tunnel test work by reverse velocity, in reality if it is quit nice sunny day with no winds only our car is moving when the atmospheric air is stationery and the road acts as a wall, when we model this in wind tunnel we reverse the reality making the car stationary and moving the air with the speed of the car. So by using inlet of 30 m/s air you already model the speed of the car so you don’t need the road to move in your case, just wall condition will do the work.
To see the vortices you should increase your mesh quality and run your simulation till it converge, I think your simulation run out of memory on a way of 50%.
Regards