Are you sure they still do this? I haven't gotten a Black Car for an X fare in several years. Used to be fairly common, now never. Before the Susan Fowler allegations, I was a 2-3x per day rider (I'm now mostly using Lyft).
However a) I can't just call him adhoc b) he's good so he's busy. So sometimes I don't get him. Then I just plan on a Lyft.