Emissions: Weather's been a bit balmy of late, has it not? It's been hotter than an Iraqi tank in my car this past week.
Not a pleasant experience at all getting stuck in traffic in a car whose sole defence against its driver being braised in his own sweat is a minute little fan in the dashboard. Even less fun when said fan is permanently stuck on hot.
Opening the windows is no solution - there's only so many times you can endure some passing peasant's cigarette ash being blown into your face and so many times you can be subjected to the heinous sound of Joe Duffy's whine from other people's radios before you start getting Medieval on people's asses. Nothwithstanding the fact that few courts could convict in the face of such provocation, I'm not taking the risk.
My pain is made all the worse by the proliferation of convertibles on our roads. One inkling of sunshine and Irish motorists get their tops off quicker than starlets at the Playboy mansion. Where do these cars all come from? Are we so rich as a nation people now have summer and winter cars like they have summer and winter wardrobes?
I'm in two minds about chop-tops. For 98 per cent of the year, they look irredeemably sad and pointless. Like Belgium. Ireland isn't called the Emerald Isle because of its precious gem deposits. Those fields didn't get green by being thirsty.
But then the three days a year when you can cruise around in the sun thinking you're a superstar make up for all the withering mid-winter stares from other motorists, for all the muggy water that's trickled down the back of your collar from the hole in your roof courtesy of a yob with a Stanley knife, for all the hours of looking lecherously at other motorists and their firm, curvaceous roofs and kicking yourself for your frivolous choice of car.
Or do they? There are pros and cons. The pros are obvious. The cons, on the other hand, are less so.
First, you can't strap surfboards to the roof of a convertible. Actually, that's not strictly correct - you can strap surfboards to the roof of a convertible, but only if you accept they are going to come off and fly backwards, decapitating a van-load of orphans on a day trip to the beach in the process. Your call.
Second, you can't park them anywhere with the roof down. Do you remember those decorated cows a few years back that had been displayed in public places in cities all over the world with nary a scratch to show for it until they arrived in Dublin, only to be targeted by the nation's finest vandals? A proud moment in the annals of Irish history, you'll agree.
Convertibles are the decorated cows of the car world. Leave one for longer than 10 minutes on any street in Dublin and you are liable to find on your return it has been turned into a makeshift skip. (I blame the bin charges, personally.)
And that's if you're lucky. The drunk Irish teenage male is not the cleverest of creatures, but even he can see that the height of the door on an average convertible is remarkably similar to the height of a urinal. And so can his mates.
Which brings us to three. Birds. I wouldn't be so vulgar as to expand on this point - but let me say I knew a chap who knew a chap who knew a chap who so envied his neighbour's convertible that he would sneak out and feed All Bran to the local magpies whenever the weather forecast was for blazing sun the next day.
Don't mean to be churlish about convertibles. I'm not jealous, honest. I'm merely giving a few things to think about before you run, loan approval in hand, down to the car dealers' forecourts, blinded by the sunlight.