Thanks for those comments.

First, I got an idea, adding some traffic to the game, then make it freak out when the storm is coming, anyway.

For the car, the movement is good, but I really think I will work on a good car model, with a human inside.

For the flashes and lightning strikes, I see that the youtube video quality is too bad to show them, because it's already in the game! Let's show you a good-quality (well its not a perfect quality but i dont want to upload a big file) video:

Video here, WMV, 11M

At the start, you can see the weather conditions taken by tephigrams (real storm chasers are using this) then you can start playing. In this video, the conditions are very good, so the storm is dark and strong. There is no tornado system in the game yet, but check it out, the lightnings are pretty impressive

Check out a big one at 0:24 in the video