I am booking a car in Feb 2019 and found that a coupon code I had been using, MUWZ094 (and others in that series), did not work for that date; IIRC, I had thought that it was because the base rental amount was too low but when I clicked on the "Learn Why" link, it advised that the code expires on 12/31/18. I found these codes in an Internet search and they appeared to work for a February 2019 reservation: MUWZ050 for $10 off base rate of $100, MUWZ054 for $15 off base rate of $125 and MUWZ055 for $25 off base rate of $175. The last one only yielded results for SUVs and similar assorted beasts; no passenger vehicles.

These were used with the U024100 BCD and one I tried from my employer; the coupon worked with both but the U code gave a slightly better price.

Interestingly, the T&C did not look too promising, "dollars off applies to base rate which are the time and mileage charges only, on a minimum base time and mileage charge of [$100,$125,$175 respectively]" and "rental must begin by June 30, 2018."

Regardless, I booked a four day rental in LAS starting Feb 24, 2019, with a base rate of $113 and the MUWZ054 knocked $15 off the price. Miles for this rental are unlimited.

These codes have been posted before in the FT forums in a Hertz thread. I did not locate them in this thread though via search.

I have gotten great information and saved a good deal of money with the information in this thread. Thank you to everyone who has contributed.