Pop the rear window and run some rope or bungees around the frame and secure it under the rear somewhere.
You should be fine as long as your not driving long distance or on the highway.
2014 - Altitude - Billet Silver
DDM 5k HID, VLed 5k led fogs, 15% tint, Mopar Slush Mats & Cargo Mat,
Black Gorilla Lug Nuts, 1.25" Bora Spacers, Black Overland Mesh, Curt Hitch
Next: SRT Springs, JL Stealth Box & XD300/1, OEM Rearview Camera