I had the same problem on the jtd, the clips were rusted to bits and the plastic case was broken where it clips through, my solution was to make some with a stainless steel wall tie used by brickies. You can flatten them with a hammer and bend them with mole grips, what I done was buff wee spikes on both sides and dig them into the filter housing, the stainless had enough spring to clamp it tight, and not fall off, I did have the box removed when I was doing it as I was replacing the boost solenoid and all the turbo vacuum piping at the time.
