Thanks again!
Oshyan, the road is meant to be wet from rain. I think it's not too reflective. The reflective shader is already broken up, so it's not a perfect mirror. Maybe I can add some more displacement to make it look better. Anyway, I won't uncheck ray trace reflections. I like the reflections of the objects very much. I already did some tests adding rain to the scene by using my own rain clipfile, but haven't found a good look so far.
I haven't tested it, but as far as I can see rendering times weren't too high compared to a version without any reflections.
And yes, I'm going to finetune this thing some more. From time to time I need a break from a scene I worked on for a long time to get some fresh eyes, hoping I don't forget how I did things...
At the moment I'm rendering a different view just for fun looking upwards. And I found out, that for the last 100 frames of this (originally) 200 frames animation the connection between the funnel and the sky looks way better.
So maybe next time I'll render the other half.