ETG Dillution or synthetic urine

So I am curious about dilution of ETG tests. If a test shows up dilluted for other drugs (i.e. THC... etc... ) will EtG still be present in that diluted sample, or will a retest be ordered for false negative?

Is synthetic urine a possibility for passing an EtG test without diluting?

Lecture me if you must, but an answer would also be appreciated.

ETG Dillution or synthetic urine