THESE are nervous times. There was a yelp from the passenger seat when Yanis Varoufakis, professor of economic theory at Athens University, mused in a radio interview on what would happen if Greece declared its departure from the euro over the weekend.
The good professor meant it by way of illustration, but my fellow-listener took it as a forecast. She was all for heading to the bank with a suitcase to take her money out there and then.
I wonder if anyone actually did that? This is no criticism of Prof Varoufakis, whose interview was a paragon of common sense. It is, rather, an illustration of the state to which we have come in this ever more febrile crisis.
Lots of money has, of course, already left the Irish banks, and the Greek banks, and probably other banks. Many ordinary Irish savers are probably running currency risk by having their money in sterling accounts. They might gain -- but they might lose.
This loss of deposits must rank highly among the many inexplicable failures of the eurozone authorities. It is not remotely good enough to treat runs on banks -- which is what this amounts to -- as a temporary emergency and cover the losses with short-term loans, as the ECB has done.
The difficulty about doing anything more sensible is the same one as bedevils any movement on the crisis -- that one thing inevitably leads to another, in directions in which people generally do not want to go.
It would be a great help, for instance, if the ECB gave longer-term loans to the banks that need them, and if it stood behind guarantees to small depositors.
But to do that, it, along with governments, would have to sort out good banks from ones with doubtful long-term prospects, and embark on closures, mergers and recapitalisations.
Since this has proved politically impossible -- so far -- we get measures that prevent immediate collapse but do not remove the threat of it.
As people and institutions respond to that threat, whether by withdrawing funds or declining to spend and invest in the real economy, the scale of any eventual bank collapse grows and economic output suffers now.
This has been the Irish experience so far, and it may become the wider European experience. The latest analysis and forecast from Davy Stockbrokers concludes that Irish households have elected to take a double hit to their standard of living.
They have added to the unavoidable one from higher taxes and reduced pay by choosing to spend less of what they have left as well.
The savings rate appears to be 13pc of income at this stage. Much of this is paying down debt rather than adding to deposits -- in whatever form -- and one would expect that, given high levels of household debt.
But it seems safe to assume that some of it is a response to the darkening European and international outlook.
They have darkened all year, with the emergency summit in July as the Greek crisis began to spread, and the even more worrying current difficulties as Greece runs out of cash and the big peripheral economies face downgrades.
It will be some time before there is data to tell how Irish consumers react to this. Today, we will get figures for the second three months of the year.
Consumer spending took a shocking 2pc dive in the second quarter and there may be some rebound from that.
But the very sharp fall in consumer confidence surveys, which approached the 2009 lows at the depth of the collapse, must owe much to the eurozone crisis, which does not bode well for future spending.
Now the World Bank has warned that a similar phenomenon threatens the more creditworthy countries in the euro area.
The post-crash years were the remarkable occasion for an increase in German domestic demand, after a decade of stagnation. German consumers have the finances to continue boosting economic growth, but they are famously cautious.
Worries about the bill that German taxpayers might face to keep the monetary union together, added to probable weakening of exports as the global economy slows, could easily persuade the euro area's most important consumers to spend less and save more.
There should be no surprise about the recent gloomy forecast for the eurozone's economy from the EU Commission.
It did not predict actual recession, but it is hard to recall an "official" forecast that ever did.
Even unofficial ones have difficulty with recession forecasts, since the mechanics of moving into declining output are not too amenable to mathematical modelling.
But, of course, recessions do happen, even if some right-wing analysts, especially in the US, seem at times to confuse what they can put into their models with what actually goes on in the real world outside.
It would take very little slippage to turn the commission forecast into recession -- especially next year, although the forecasts do not look that far. They do see growth coming to a virtual standstill towards the end of this year.
The commission did note that surveys of business and consumer confidence and intentions deteriorated sharply since the first quarter. "Financial market stress is set to dent confidence and increase investment cost," it observes.
Equally unsurprising was Brussels' call for continued "growth-friendly" fiscal consolidation in member states and implementation of the July decisions on financial stability.
Many doubt that there is such a thing as growth-friendly fiscal consolidation, but even if the sight of such consolidation can increase confidence, it will certainly not help growth if the confidence is then undermined by what often appears to be an inexorable drift toward some kind of terminal crisis.
The banks are at the root of this. The plunge in leading European bank shares and the pressure on inter-bank lending indicate that markets now expect the banks to face up to sovereign writedowns and other bad debts, incur large losses and require lots of fresh capital.
The best thing euro-area governments can do is prove the markets right, and begin the long, painful process of building a system in which ordinary folk outside the markets can believe, and even trust.