Responding to your IM, I think that increasing the PM Shine would make it look even more like plastic. I think what you need is not more shine, but more bump, to make it look like beads of sweat.

Here is a quick test (click to view full size) I did using a noise node (it might be better with a spots node, I didn't get that far). The sphere on the left has just specular, while the one on the right has an extra specular node applying noise to the bump channel. You will have to play around with the node values a bit to get it right.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)