This past year I have been renting from Enterprise bi-weekly. Just wanted to share some tips with you.
The rates they qoute you are like gel. They can be moved and brought down very easily. Here are a few of them.
1.) If your not a frequent user of that particular location, tell them your car is in the shop. And your insurance company is paying you 20 dollars a day to rent a car. Since there are insurance rates, which are much cheaper. They will give it to you. They will ask for a claim number. You can tell them you misplaced it. This can work a bunch of times.
2.) Call them and tell them a nearby Dollar is offering a daily rate of e.g. 30 a day. Then ask them if they can match it.
3.) Any complaint you make on the car, can give you discounts. Because they have a customers satisfaction option, which will take off the rate that they give you. E.g. "The car had a horrible oil smell", "There was no washerfluid left", "The car was making loud noises". Basically tell them, you were horribly inconvenienced.
4.) Not officially, if you tell your rep you will send headqaurters a letter how well they took care of you, always helps.
Other tips
a) You can always get an upgrade for free, just ask nicely.
b) You can rent at the end of a day, and they can start the billing the next day for you. (only if its a 24hour billing, not an insurance rental which bills by day)
Good luck!!!