The problem with your first video that you attached was it was not in English, which obviously, made it very hard for me to understand, to say the least.
The second one, would have been a lot better with a verbal step-by-step, instead of the music and the writing of the steps of what they were trying to accomplish.
I posted a thread a long time ago about how to make a reflection underneath an aircraft. Perhaps you could find that thread on here and possibly gain some insights that would help you as well. The folks on this forum have been extremely helpful to me and I'm sure others will reach out to you with some other suggestions.
The real problem here is that creating reflections is only part of the solution. It does not create the "wet" effect that I think the OP is searching for.
Example. Here is a cobblestone street with a reflection.............looks nothing like the wet streets in the OP's examples. There's much more involved with this effect than just creating reflections. I'm working on it. If I find a decent solution, I will post it.