If you have a gun in a guitar case because you don't want anyone to know you have a gun, then you are concealing it and that is illegal.[/QUOTE]
The issue of "carrying" and "transporting" is being confused here.
If you are " carrying" a LEGAL sawed off shotgun down the street hidden under your full length "oilskin" raincoat, and its not raining, and you're loitering having "having a smoke" outside a bank ... yes I suspect you would "come to the attention of" the local LEO!!!
BUT! Much better to have it in a bag slung over the shoulder or wrapped in a black plastic garbage bag than to have the naked gun (even with a trigger lock attached) slung over your shoulder!
However the TRANSPORT OF NON RESTRICTED is a different situation. I have a mini van - no trunk and back seats removed. While the vehicle is "attended" the only requirement is they must be unloaded. When the vehicle is left UNATTENDED NON RESTRICTED firearms must be locked in a "trunk" or a " similar lockable compartment" in this case the entire LOCKED min-van compartment BUT with the caveat that one shall " put firearms and firearm containers out of sight inside the vehicle and lock the vehicle." In this case I WOULD cover my long guns with that full length "oilskin raincoat" not in an attempt to "conceal" but to avoid the "temptation" of a "break and enter" similar to the situation of "concealing" cameras, binocs, computers, cell phones and iPads in vehicles even if the vehicle IS LOCKED!
The old saying "there's not a problem, unless there IS A PROBLEM, THEN! THERE IS A PROBLEM. As always a little "common sense" will generally avoid nasty outcomes!