I have a 2003 E500 Sport. Rear end sags way down after being parked for 24hrs

I own a 2003 E500 and it did the same if it didn't get driven for a week it would sit on the garage floor until it was started. After raising the car to get a good look at the rear air bags I located 3 air lines at center of car near the differential and found one line marked with green had a small leak. I tightened the fitting and it solved the problem