As freezing some vertices in the cloth is quite an artificial way to create a result, the question is: what’s the alternative? What happens when I just put a heave object upon the cloth? Let’s find out.
Then (from Pose Room) I put a small (cylinder) object upon the cloth
I leave the car to its defaults.
Third, I give myself the proper start position with [Clear Simulation] and by setting the proper Morph dial to 1.
And, in the cloth properties panel, I check the Collision Friction option. This tells the simulator NOT to use the values below from the cloth object, but to use the values from the collision objects instead. And that means that the clot will experience extreme frictions from ground and pylon object, and default friction from the car.
My result looks like this:
Frankly, the 0.1 dynamic friction is quite high for cloth sliding over a well lacquered steel car roof anyway, and so is the static friction of 0.5. Both can be lowered at our liking, but when doing so it has to be done in the Collision Objects collection as the sim uses that info instead of the friction from the cloth parameters.