The free Hertz Rewards program is a solid option to consider, especially if you have credit card perks that can give you status &/or reduce your costs.
Options for Instant Status & Lower Costs
US Daily Award Chart
US Weekly Award Chart
US One-Way Rentals Award Chart
How to Redeem Points
Where Can You Redeem Points?
International Award Charts
AnyDay Rewards Dates
Up to 20% Off for those Over 50
Minimum Age 21
Base Membership Benefits
Status Tiers
Related:
Points Purchases (how my dad got >90% of his Hertz rewards)