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.
coming soon... 2015 Altitude - Billet Silver
Park Sense, Backup Camera & 9 Speaker Audio
Ready to install: 1.25" Boras, Gorilla Black Lugs, Overland Black Mesh,
4" Chrome Tips, Polk Center Speaker and Sylvania Ultra H11 - Lows & Fogs
Previous: 2008 WK 4x4 & 2014 Altitude - Billet Silver - Lemon!