Autotrail Imala 620 2016. Noticed the outlet/tap on the grey waste seemed a little "wobbly" so checked it out. The underslung tank has a pipe attached which terminates at a large tap at the edge of the vehicle. On the pipe, close to the tap, is a fitting which has a very long threaded stud, attached to another fitting on the underside of the vehicle floor. The floor fitting was loose, one of the two screws appearing to have ripped from its hole. While examining the stripped screw and considering how to repair, I noticed quite a lot of forward/backward movement in the pipe, with a little liquid dripping from the bulkhead fitting on the tank. The job seemed to becoming bigger. Ok, I removed one of the two large inspection covers (a big screw-on cap) and got an expected trickle of dubious water on my face. Reaching inside the tank to the fitting resulted in retrieving a large plastic nut, used to secure the tank fitting on the inside. It was broken, no longer holding the tank fitting tight. I purchased a new nut (this time brass) together with a couple of rubber washers/seals and refitted, then replaced inspection cap. I then made a metal plate to fit to the underside of the floor, to re-attach the upper stud mount, this time adding a locknut to the stud. The poor OEM build has now been improved by me and I doubt will give further problems moving forward. I have however noticed another problem, probably also connected to the original one. The waste tank is held in place with two metal straps secured to the underside of the chassis. These two straps run in line with the vehicle, front to back. The vertical faces of the straps are wider than the width of the tank, with around an inch gap each side. I found that I am able to grip the tank and move it back and forth between the strap faces. As the discharge pipe/tap is fixed at the tap end, I wonder if the tank has been moving forward/back putting strain on the discharge pipe? Also, is the tank able to move left/right in addition to forward/back, thus creating another possible problem? I think I need to take another look at the tank and its mounting to see if it requires further work to improve what appears to be very poor attention to detail by Autotrail.