First bid was at $15 for a Mid-size which was rejected. Priceline responded with a counter offer of $20 which I passed on.
I then immediately re-bid at $16 for a Full-size car which was accepted by Hertz. Full cost was $173.54
This is at least $60 less than the best "total" price I could get shopping individual car rental company sites for a mid-size or smaller car, even including whatever appropriate coupon I possessed.