Welcome to the forum and congrats on the purchase.
If your Challenger is like my ND you can increase the airflow through the vents by closing the vents on the AC grills.
Also on mine, the front AC will feed air through all of the vents (front and rear) and vice-versa even if one system is turned off.
Mods I have done to my Challenger include, but are not limited to
- Sound proofing the dog house
- Modified the fresh water tank drain so I can sanitize the water hose at the same time I sanitize the rest of the fresh water system
- Swapped out the living area Seiki TV with a 46 inch Sharp Aquos