When the b*tch clip is installed properly it should NOT come loose from vibration. From the few SSK that I've been working with, it can be very hard to put the clip back in as well, but once it's in it should sit FLUSH with the transmission tunnel. The reason why the clip is impossible to remove in the first place is why it should not come lose, there's a small tab that catches the inside of an indent on the transmission tunnel that makes it impossible to remove the clip unless you can drop the transmission.
If that thing came loose, then it's not properly installed.