Just wanted to give a big thank you to all you wonderful people about the advice to check prices frequently and for all the recent posts about car rental price drops!
I have been checking and seeing slight decreases. I just checked (again) this morning and was able to rebook for $100 less through Costco - both Enterprise and Alamo dropped this morning (I originally had Budget.)
Discount Hawaii Car Rentals was also down significantly, but not as much as Costco.
This is for the beginning of September.