Have you tried booking a rental car through Costco? I recently canceled my reservation with Enterprise (using my company's code) because they were more competitive for our family vacation.
i actually did this last time we traveled as it was the best deal for me through enterprise- i will only rent cars through enterprise or national because i've had issues with other carriers before and it's 10000% not worth the $96 you save across a week long rental to have that headache