i know exact symptom your speaking of. The fact you thought was an ABS issue was dead giveaway. and you won't like what's causing it.....
Its last death scream of your dying throwout bearing.
My car did the exact samething - I thought was ABS too. happens ramdomly, and disappear randomly. seems like brake and clutch pedal is vibrating(almost like resonating now that i think abbout it).
about month and half after this started in my car, I blew clutch apart.
What happened was (the best we can figure), was that one or more ball bearing inside of TB was worn (no longer round - You know the well documented "bird chirp" with our car?), allows uneven pressure to be applied to clutch disk(because due to worn metal ball, it was wabbling - which is the vibration your feeling transmitting through the tout metal clutch cable), and when oneday I try to take cool video of my car smoking tires - applying alot of power to now unevenly applied clutch - clutch couldn't hold it, and let go.
It could be something else. But i bet my left testicle its your TB
