@tsarstepan,
It has been pointed out several times that Trump is free to release his tax returns whether he is under audit or not. Also, every incumbent president is under audit automatically, yet all of them released their tax returns not only when running for president, but while president.
The audit excuse is just that-an excuse. It more and more seems obvious that Trump wont' release his tax returns because they reveal where he gets his money from, and much of that money is from Putin & Friends.