Originally Posted by
memoses
My suggestion is this: Start with Executive status (through whatever means or just eventually get there over time), and on an evening like Sunday or Friday, head to the airport and scour the Executive aisle for your favorite car (the lot should be chocked full on those days). Rent the car one way to a local branch under an FCAR contract. At the branch the next day, have a long-term FCAR contract waiting, and when you arrive at the branch, just ask them to keep the car you have and swap the contracts. The branch will usually be happy to oblige with processing the upgrade because you are now giving them money instead of the airport while at the same time not removing any of their inventory. It's basically free revenue for the branch.
This works for many local locations but not all - Boca Raton as one example where the manager is specifically and deliberately mean spirited about taking away any car that falls outside your reserved class regardless of status.
The one-way one-day deal is the best use of free days as you can often get something in the premium or luxury category and then with a cooperative (which generally improves over time and frequent rentals) local office, keep it until you need to travel again and drop it back at the airport - where getting the car back will often net you an improved selection when you rent a luxury or premium again - while taking their prized inventory and giving it to the local office will often yield worsening options on future rentals.
Just keep both sides of the bread buttered and you're good to go.