This is weird. I could swear my last rental, my first-ever prepaid, earned Hertz points (in triple). I'll have to check.
EDIT: Confirmed on Hertz.com, earned points on the prepaid amount $45, plus extra bonus of 90 so total of 135 points.
The process was a little odd, with the prepay only of the rate amount, and tax/etc paid at return. Even the agent (though I think a newbie) was a little surprised, she thought it was a big coupon or award or something, heh. And I had to think about it for a sec before finally realizing and saying no no it's a prepaid rate.
Also I distinctly remember that even my printout at rental said I would earn 135 points. I was impressed the computer knew already that the triple points applied, because even now we don't always expect things like that to be correct.
The rental was in late September.