It's very easy to use a code. Click on "Show coupon code". Copy the code and look out for the opportunity to use it.
Now that you have a code, let's use it:
1. Go to dollar.com.
2. Pick a car, choose a pick up location and the dates you will need and return the car. Fill in the other necessary information.
3. There are many options to save, pick one and click on "Get rates".
4. Notice the field for the code, paste the code from discountreactor.com into this field and click on “Get rates”.
That would be all.