sunroof pops open with a push of the hand

[moxwell]

Hello all, my sunroof in my 300sdl seems to get depressed when traveling at highway speeds. It seems the wind pushes it down and it begins to make a whistling sound and if it is raining it allows rain in. I was wondering if there was a way to manually lock it in place. It currently does not work and I never used it, I was even considering welding it shut and just redoing the headliner. Currently it only tilts open but does not roll back. I usually have to help it back down.