AutoSlash: How to Get the Lowest Price on a Rental Car

And Do So with the Least Amount of Effort

When renting a car, I want to get the cheapest rate possible with the least amount of effort. You, too? If so, you need to use a free site called AutoSlash. I’ve used AutoSlash dozens of times since 2011. On one occasion, AutoSlash saved me a whopping $2,178 (74%) on a 27-day SUV rental. On at least 10 separate occasions, AutoSlash saved me more than 31% off the lowest rate I could find. Due to its considerable savings and ease of use, I highly recommend using AutoSlash every time you book a rental car.

Woman in rental car holding car keys

In this post I’ll explain what AutoSlash is and show you how to use it to quickly save a ton when renting a car.

What is AutoSlash?

Simply put, AutoSlash ( is a free site that tries to find you a lower rate on most any car rental you book.

How Does It Work?

The simplest way to use AutoSlash is, first, to reserve a car however you typically book a car. Once that booking is complete, head over to AutoSlash and click on the tab that says “Track a Rental”:

AutoSlash - track a rental car tab

Then, provide AutoSlash with your name, email address, rental car company, confirmation number, pickup-date, and reserved price for your rental. You can include any organizations or clubs that you might belong to (such as AAA) that could help AutoSlash get you the best possible rate:

AutoSlash track a rental car information screen

Finally, click “Track.”

AutoSlash then goes to work. It doesn’t change the date, time, pickup location, drop-off location, or car type of your rental. Keeping all of those items the same, AutoSlash tries multiple times per day to bring your rate down by applying coupons and discounts. [Edit: If an upgraded car type is cheaper than your originally-selected car type, AutoSlash will provide you with the option of upgrading your car type in order to take advantage of the lower rate.]

If it finds a lower rate from the same rental car company, it automatically re-books you so as to lock in the savings, and it emails you your new confirmation number. If it finds you a lower rate from a different rental company, it emails you with instructions for how to rebook yourself.

My Experience with AutoSlash

I flat out love AutoSlash. As I mentioned above, I’ve used it dozens of times to save money on car rentals. And because it is so easy to use, the savings feel like free money.

Last weekend I conducted a test in which I created 10 car rental reservations for 10 different car types, in 10 different cities, spread out over the course of the next 10 months, for 1-7 days rental length each. I submitted those reservations to AutoSlash to track.

Within an hour, AutoSlash had brought the price down on 6 of the reservations by an average of 14%. Two days later, it had knocked 5% of a 7th reservation. And it will continue to work on all 10 bookings up to the pickup day for each of them.

And in my experience, AutoSlash is all the more powerful the more days you can give it to work. That is, the further out your car rental reservation is, the more days AutoSlash has to get you a great price.

As an extreme example, I once booked a car in July of 2014 for a Thanksgiving trip four months later. The best rate I could find at the time of booking was $185.42. For more than a month, AutoSlash couldn’t find a better rate. But then, over the next several months, it found these progressively lower rates:

  • 8/21 = $173.30
  • 9/4 = $168.01
  • 9/17 = $158.53
  • 9/22 = $148.53
  • 9/25 = $143.25
  • 9/29 = $137.99
  • 11/4 = $113.74
  • 11/8 = $85.47

In the end, I paid $85.47 rather than $185.42. AutoSlash saved me $99.95 (54%) with minimal effort on my part.

Pro Tip: For a really inexpensive trip, combine AutoSlash for car rentals with this Priceline trick for hotels.


AutoSlash is genius. It makes saving money on car rentals so easy that I enthusiastically recommend using it whenever you book a car.

Question: Have you used AutoSlash successfully before? If not, will you use it moving forward? You can leave a comment by clicking here.

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10 thoughts on “AutoSlash: How to Get the Lowest Price on a Rental Car

  1. Great post, Brian! I have a question…If you track your car rental with Auto Slash, does that mean you definitely have to rent a car? I’ve got a trip coming up, and the car rentals are more expensive than if I planned on taking an Uber everywhere. Is it possible to track it with Auto Slash, and if it goes down to a reasonable amount, keep the car rental, but if not, cancel the rental and do Uber?

    • Great question, Jessica. Thanks for asking.

      The reservations AutoSlash guides you to are 100% cancellable, like the vast majority of car rental reservations. In fact, just as is also the case with most car rental reservations, with AutoSlash bookings you don’t even technically need to cancel them to avoid paying. If you don’t pick up the car, you won’t pay. That said, I imagine that car rental agencies appreciate when you cancel the booking if you aren’t going to pick up the car.

      So in your case, what I would recommend is booking a car, submitting it to AutoSlash, and letting AutoSlash go to work. If AutoSlash brings the price way day, great! If not, then you can cancel the reservation and use Uber.

  2. Thanks Brian! I put this right to work with 3 reservations and within an hour, all 3 came back lower! However, I book rentals through a company travel agency and then insurance coverage is provided for company trips (which these are). I’m nervous to take the lower rate when it’s book through sites like Priceline because I worry that company connection might be lost and I have to pay for the insurance. Have you had experience with this? Do I need to worry about it? Or is booking through a company travel agency possibly an exception to this trick?

    • Rachel,

      Great question. I’m 99% sure that re-booking through AutoSlash will break the link between your prior booking through your company’s travel agency. So, unfortunately, you will lose any insurance coverage provided through your company. 🙁

      Thanks for commenting as I’m sure others have this question as well.

    • Thanks for your question. Who you book through is less a factor than what discount code is used on your booking. My guess is that all of your corporate car rentals are booked through the same company (likely Hertz, Avis or National) and the discount code used for those bookings automatically adds insurance based on the deal your company has negotiated with whomever their preferred company is. Since AutoSlash has no knowledge of your company’s negotiated rates, or the associated discount codes, those benefits (like insurance) would not apply, however feel free to email us at, and we’d be happy to investigate further. Often we can identify corporate discount codes, lower the rate, and book you through us, and all of the associated benefits would apply. We’d be happy to check into it for you. Hope this helps!

  3. Another excellent find and thorough explanation as a result of sound researching!

    This is Travel Tips 301 with really useful and valuable techniques taught.

  4. Great post Brian… I do not travel much so to be honest with you I was shocked at the prices of renting a car for 10 days! anyway, I need to rent 2 cars for our family vacation to Colorado (1 small car (3-4p) for 7 days; 1 (5p) for 10 days). I cannot find anywhere how to get rates for a double booking? When we fly in I really don’t want to burn extra hours going between 2 places to pickup the rentals? Can Auto Slash orchestrate/accommodate that?

    • Hi Lance,

      If I understand your question correctly, I think you could just book the two cars at whichever agency has the lowest overall combined price for the two cars. You can then submit them to AutoSlash.

      Whenever AutoSlash comes back with a lower rate, you could book that lower rate while not cancelling either your original bookings or any subsequent bookings you make on cheaper rentals, per AutoSlash’s alerts.

      Then, the night before the trip (or whenever), you could review all of the bookings you have and pick whichever two provide the lowest overall combined rate from the same agency.

      That all said, I have two further thoughts.

      First, I’m not sure it will be very burdensome to rent from two different agencies. Because I am from Denver, DIA is about the one major airport from which I haven’t rented a car. So I can’t say for sure that the agencies are in the same place. But at least for the major agencies, they usually are. It could be worth investigating.

      Secondly, I heard once that there is a rental agency not far from DIA that, because it isn’t technically one of the airport agencies, is much cheaper. When I heard that (which was more than 5 years ago now), the person who told me it said there was a free shuttle that ran between DIA and that agency. Possibly worth looking into as well.

      I hope you have a great trip and get a great price on your rentals!