This page of our Saints Row trophy guide explains how to acquire the Free Refills trophy. We explain how to unlock the Infinite Boost, how to install it in your car and how to use it to earn the trophy.
Buying the regular Boost
Infinite Boost is a signature ability of certain cars. It functions as an upgraded boost you can use without any limitations.
One of the vehicles you can use to earn the described trophy is the Varsity pick-up, as it's common and easy to add to your garage.
Enter the tuning tab in the garage, then select Equipment. One of the possible upgrades is Boost, which will cost you $7,500. Purchase it and install it.
Unlocking the Infinite Boost
You must use the regular Boost in order to unlock the infinite one. First, drive out of the garage.
You must fully empty your boost tank three times. This means that once you start boosting (hold L1/LB on the controller), you can't let go of the button until the boost runs out. Long and wide roads are the best places to do so at.
Once you manage to fully empty the tank three times you'll receive the notification about unlocking the ability.
The signature ability must be activated manually, it won't work right away. Return to the garage and start tuning the vehicle again. As pictured above, you can now enable the ability.
Using the Infinite Boost for the trophy
Drive out of the garage yet again. Now find a long stretch of road, such as the highway. Wait for the boost tank to fully charge, then hold down the boost button and don't let go. Your boost meter will be constantly replenishing and you won't stop boosting until you let go of the button.
You need to drive like this for at least three full cycles, each cycle ending with a distinctive sound cue. After the third sound cue let go of the button to earn the trophy.