The mechanic pointed to a button on the dashboard which locks all the car doors at a single touch. "That must be right handy when you're visiting Dublin," he observed. That's one of the cliches about the Big Smoke down south that northerners subscribe to: you're not safe on the streets. But more often one hears a note of envy.
Like characters out of Chekhov or Lennox Robinson, the northerners lilt: "Ah, Dublin, I love the place. I always have a great time. There's so much to do. The restaurants are fantastic and they get more big names to do concerts and the craic is tremendous. I can't wait for my next visit to Dublin. I'd love to work there - any jobs going?"
Down south, one encounters no great hunger among friends and acquaintances for a visit to Belfast. That's a pity because the new train service is fast and comfortable and there are eight departures a day from Connolly Station. You could also try it by road, if you're prepared to risk being snarled in traffic at Balbriggan or Drogheda or on the way out of Dublin itself.
But the weakness of the pound against sterling means most of the traffic is going the other way these days. Only occasionally does one hear a southern accent in the Belfast department stores. God be with the days when Belfast was a place you went shopping, and the troubles were a distant nightmare.
Now, like Rip Van Winkle, Belfast is awakening from decades of stony sleep. The security presence is being scaled down although it still jars when you see RUC men in flak jackets wending their way through downtown crowds. Since I got here I seem to have had my own personal British Army helicopter, whirring above my head from time to time with peculiar insistence.
Ground control to Apocalypse Now: Go back to base, the war's over.
The troubles may flicker back to life now and again, as they did so dramatically over the weekend, but there is a palpable war-weariness in the Belfast air. If there is a settlement or at least a continuing non-violent stalemate perhaps the city will have a chance to blossom forth like Dublin has in recent years.
`I suppose you have realised by now," said an old Belfast hand, "that socially this place is a non-starter." It's true that Belfast is considerably quieter than Dublin. There are fewer people on the streets at night, and socialites complain that the incidence of dinner-party activity is a good deal lower.
Dublin, on the other hand, has lost the run of itself. Vast crowds pound the streets, even in the rain, marching out before the traffic with suicidal determination. There is a new brashness, vulgarity and abrasiveness about Dublin that Belfast has yet to acquire. Accidentally I got in the wrong lane at Stillorgan and blocked four youths in the car behind from making a right turn. I could see them in the mirror howling a variety of epithets beginning with the letters F and B, like dogs baying at the moon. Road rage in Stillorgan - is this the end of civilisation as we know it?
If de Valera was alive today he would be more likely to encounter his ideal of frugal comfort in Belfast than in Dublin. The Celtic Tiger has not crossed the Border yet, although some businessmen up here would dearly love to grab his tail.
If the troubles come to a final halt, Belfast may well recover its reputation as the Athens of the north. It's not lacking in cultural activity as things stand. The Belfast Festival at Queen's has been well covered in this newspaper. At other times of the year also there is theatre, music, cinema and a variety of other attractions.
The Waterfront hall is the jewel in the city's crown. Architectural critics have swooned in ecstasy over its design. One hears occasional complaints that it lacks atmosphere, but already it has staged some memorable concerts. As the area around it is built up and becomes more populated, so too the atmosphere will no doubt improve.
There is a little too much splendid isolation about the place at the moment.
One respect in which the two cities are converging is in the sphere of drink-driving. In Belfast it is commonplace for people working in the city centre to drive home and get a taxi back if they are meeting friends at a pub in town. The noose is tightening in Dublin too - and so it should, of course.
The consolation in Belfast is that, in my experience, taxis tend to be cheaper and the price of the pint lower than in similar hostelries in Dublin. Meanwhile, the manic property boom seen in Dublin has not gripped Belfast to the same extent. The troubles drove down the price of houses, and friends on modest incomes here live in palatial homes a few minutes from the centre: down south they might be lucky to have a semi-detached in Lucan or Celbridge.
A smart and cynical financier would invest heavily in property here and print a few thousand leaflets on the side, encouraging a settlement.
Ironically, the decline in paramilitary violence was accompanied by a rise in community tension. The shooting acted as a safety-valve, and people probably worry more now about being in the wrong place at the wrong time, where the "other crowd" might get them. But it is a moot point whether a Catholic is safer in a Protestant ghetto in Belfast than a man in a suit carrying a briefcase in one of the poverty traps that dot the Dublin landscape.
When our putative party-going Belfast-dweller reaches that city-centre pub he or she is likely to have to put up with more and louder background "music" than in Dublin. The present writer retreated to the Crown which, as well as being an architectural delight, had no piped noise. But one disease has both cities in its thrall: the dreaded soccer screens are everywhere.
How did folk live in the days before, "Yes, it's Cole scoring from a cross by Giggs, whadda fantastic goal?" We need a cross-Border movement, not just in search of peace but to recover the lost art of conversation.