StuartT, your fantastical leaps over mountains of logic and great chasms of reasoning are almost inspiring. Cars are here to stay for the foreseeable future, they are just too good are means of transportation, unequalled in their ability, at the very least, to liberate people from insular and constrictive communities.
Far from thinking outside the box, you refuse to acknowledge it even exists and thus your fanciful dreams of an all-Island rail network are so far removed from reality that you may as well construct it out of confectionary.
How buses can be judged to have failed is quite beyond me; perhaps you misjudge to role they fill. Do they not provide a relatively lost cost means of transport to those unable, for numerous reasons, to use private automobiles? The disabled, the elderly, parents, lower-wage earners, children, yound people - all are granted mobility from across the Island thanks to the maintenance of the Isle of Man Bus Company. Sure, the times may not be suitable to all, but the majority are served well enough.
Perhaps you think they failed to prevent congestion? Were they ever designed or intended to? Of course not.
If a car pack were constructed at the Cooil, with a lower daily rate that would paid in Douglas, traffic from the south would reduce, allowing easier access from along Peel road, and those parked at the Cooil could use a Park & Ride bus service. There parking ticket could even serve as their bus ticket as well.
The aim of QB scheme is to reduce congestion and accidents, which a Park&Ride scheme would do, with out your unnecessary multi-multi-million pound rail scheme, or the DoT's Super-Duper-Wuper roundabout.