Yes. With a few exceptions related to sound system options, the Modern Spare spare tire kit can be stored and secured in the space under the trunk floor.
Fortunately, the Dodge Charger and Challenger models have kept the storage "well" even after Dodge stopped including a factory-supplied spare tire many years ago. Modern Spare has designed a sturdy hardware assembly to secure the spare in this space.
This hardware is only part of one kit option for these models. Be sure to order the "Complete Kit Without Carrying Case" to guarantee that the securing hardware is included in your order. The securing hardware is not part of the Wheel and Tire Only option or the option with the carrying case.
The Charger and Challenger models that lack storage under the trunk floor are those fitted with the optional Harman Kardon factory-installed subwoofer as part of an upgraded sound system. For these models, a kit with a carrying case may be the best solution for storing the spare in the main trunk compartment.