When searching online for rates, you won't see anything set up that will offer a deal for
multiple car rental bookings. Unfortunately, the websites just aren't set up to do that.
There are a few things that you might try:
Call a few local car rental agencies and ask to speak to the manager on duty. (You can usually find local numbers by doing a search on yellowpages.com for car rental for your particular town or city.) Explain to the manager your situation, and see if he or she is empowered to offer you a discounted rate for multiple car rental bookings.
You can also check with various car rental companies to see if any are offering current car rental specials or a deal for multiple rentals. Some companies may offer specials sometimes where they will keep track of your rental history and award free day coupons after so many days of rental or number of rentals. You can also check if there are any rewards associated with becoming a member of a particular car rental company's frequent renter program .
Pages from this site related to this topic:
The Basics of Car Rental
Making Car Rental Reservations
Comparing Car Rental Rates