What in the world...how does a domestic lead to a buggered car!?
VZs are tough bastards (I do know!) so I am asserting that a pre-existing fault or problem has been unnecessarily exacerbated by some unwise, unruly driving.
Cleaning the MAF?? Why?? MAFs do not require any intervention, not even over a very, very long term, unless you have been driving through a coal cellar and been blackened and bruised and burned, at which time your MAF, just a very thin, taut strand of wire, isn't going to be the one and only warning of something wrong! My VZ MAF was never touched in 9 years. Others around here (where I live) have older VZs and have no idea what a MAF is, much less go on the hunt for it.
I'm inclined to think that from the muffler business and unstable, "flapping" idle there is a manifold leak or head leak. Idle is usually very stable on the Alloytec, unless the petrol or fuel system is fouled or spark plugs well out of service interval (as so many, many are!!).