A quick look at the POH for a Cherokee 140 reveals a bit of advice which conflicts with 'best practice' - "carburettor heat should not be applied nless there is an indication of carburettor icing" - this is standard POH guidance for PA28s.
A few years back I used to frequent a leaky hangar at the West end of Aodergrove. Hidden towards the back was GATRR, covered in guano and obviously not flown, for a long time. To think that someone declared this aircraft airworthy and, somewhere along the way, it 'lost' a couple of rear spar bolts without anyone noticing is shocking. As for the 50/150 confusion - outrageous.
Of course, the crash most probably wasn't caused by slack engineering procedures but, to me, this event highlights that we appear to be happy to launch into the sky in rubbish we would never consider driving down the road.