Thank you Gentlemen.
The car never did anything like this. There's got to be a place it comes out.
It's not much, in fact it's minimal. The original spot size is not more than a Quarter, but than the dry concrete absorbs it to about the size of an average hand.
All this happens while the car is sitting for approx. 2-3 weeks, as I already stated.
I'll keep monitoring the situation.