Hi Karim,
It should be around 6 pages long for the car, so maybe 6 minutes.
I think it would be too much hassle with bonnet mounted camera since I need to finish it in a day and would need several angles. Also it's a bit dangerous since its happening in the city and acting might suffer.
Trailer is a solution, but then I have to have more things to worry about. Rain on a moving trailer. I'm also worried that height of the car would increase quite a bit and passing cars would seem lower. Even one trailer I found made for shooting was a bit too high for my taste .
Car is moving and since its a cloudy day time scene, I'm not sure about lights inside the car. It can be a bit moody. A bit.
I was thinking maybe get car outside. cover it with 20*20 muslin or black. put a green screen on the background and using a water hose create a rain? I'm just worried about green screen and rain. How it would workout together.
My main reference is a car sequence in "A rainy Day in New York" by Storaro. It doesn't have to be perfectly real, just pretty since story kind of justifies it in a way(the Film about a daydreamer). I'm trying to understand how they shot it there.
I'll let you know what will work for us ?
Thanks!