Plz help

So there was this medal rubbing on medal sound
coming from the back wheels and my boyfriend
changed the rear end break pads,  and as we was
driving down the road we smelled something and
about 35 miles down he highway we start hearing
this roaring nose coming from the back end so we
pull over and he notices he didn't have the break
pad on right so it wasnt releasing right and so he
redid and put it on the right way but as we started
driving it started the roaring noise about 10miles
down the road and the further we drove it began to
start sounding like the roaring was coming from
the front somewhere??  Plz help me figure out
what could be my problem?