Although you may not have the full hydro suspension, many 116’s have self adjusting rear suspension, this is like a ride hight assist to help the spring and works on the basic same system as the full hydro system, if you have this like I do there will be a small fluid tank in the right hand side of your engine bay( behind the head light), a pump mounted on the engine, a pressure switch mounted on the body which connects to the rear anti roll bar and special shocks at the rear. This system works great, you will notice when there is 5 in the car and a few bags that the rear will raise and the car will level its self out automatically when the engine starts.
My guess is that the switch is not set properly. Mine was actually a tad low when I got it and the rear looked like it would sag sometimes. You are able to get under the car and adjust it yours self with a few basic tools. It is so easy I am not going to explain it because you will see for your self.
Hope this was of help