Everytime I have used this coupon (3 times), my total has been about $10-$15 higher than I had originally been quoted. However, I rented last weekend and the total upon return was around $30 higher so I went to the rental desk to get it adjusted. When Hertz overcharges me by $10, I don't bother inquiring because I usually am running late (and I didn't notice what was happening until I read this thread after the first 2 rentals), but I had time and $30 was worth spending a few minutes. Anyway, the counter agent had no idea what to do and after about 5 minutes handed me a revised receipt showing a total charge of $66 (original quote was $126, quote when I returned was $156). So that made up for the 3 previous and the next few rentals using this coupon.