not to tell someone else how to drive their car, but the ebrake really isnt supposed to be used while driving. personally i like swinging the rear end around with the skinny pedal
to that end, you may want to inspect the condition of your ebrake shoes in the rear disks. it would seem that it is not the cable if it is catching every once in a while. if its an intermittant deal, i would look at the shoes in the back.