Who else can teach you to peel a banana, pass it over your shoulder, pick up the skin, all the while changing gear, indicating, shouting at other drivers and generally keeping on the move? Patrick Logue on the thrills and the traumas of driving with children in the back.
You can imagine my surprise when, having folded up the "travel system" and put it in the boot, there was enough room for only a bottle of sparkling water, a banana, and a fold-up brolly. It was looking increasingly likely the Samsonite was going to have to go on the roof somehow.
I like my car, a modestly aged BMW 318i, but maybe it wasn't the most practical purchase for the parent and general taximan to two boys - one six years old, the other five months.
The full horror of what I had done hit me when, sitting in the passenger seat two weeks after my purchase, I took the instruction manual out of the glove compartment.
"What do you mean you cannot fold down the back seat?" How will I get the lengths of 4X2 home from Homebase, I asked the book. "It's an executive saloon," it replied in a thick German accent. "Do I look like a Skoda Octavia?"
I was beginning to envy some of my more sensible fellow motoring parents (the ones with the baby on board stickers, admittedly) who had bought mid-1990s-registered Passat estates and the like, or people carriers with acres of space but only tiny droplets of style or good looks.
There they are with their buggies and travel systems, bicycles, children, children's friends, children's friends' grannies, sisters, cousins, aunts, all comfortably cruising around (0-100 in 20 seconds admittedly) without hindrance of tight space.
"We're getting a 7-seater," a six-year-old boy, who had come round to play, told me the other day. I counted and I counted again, but the 3-Series outside the door only had five seats. It gets worse.
Somewhere in our wisdom we decided to buy a car with a cream interior. Those of you with cream interiors will know how rewarding it is when it gleams after four hours of scrubbing. Those of you with children and cream interiors will know that doing this twice a week is the barest minimum requirement to keep the car from looking and smelling like the inside of a public toilet.
So, it's large doses of "take your shoes off the seat", "if you drop that ice cream you'll be grounded for a week" and "can you please stop your baby brother dribbling on the leather." All adding to the already large dollops of stress associated with driving with chizzlers in the back.
Last month an American woman was charged with child abuse and cruetly after she allegedly forced two of her children to take turns travelling in the boot of a car on an eight-hour trip from Alabama to Virginia. Nasty thing to do, but driving with the kids is more nerveracking than your first time on the big dipper.
Perhaps there is a better way. In Britain, some areas have started using the "pink bus of shame" to carry unruly school children, the ones who won't sit down or who keep annoying the driver and fighting with each other. The Isle of Wight apparently uses a "pink punishment bus" to publicly humiliate the brats. There have been times, let me tell you, that your correspondent has contemplated a "pink trailer of chastisement" for my pair.
And I'm not alone. A survey last year showed that more than half of motorists consider travelling with a screaming child more dangerous than driving while using a hand-held mobile phone. Should Martin Cullen be seek to introduce laws banning children from screaming in cars? Or just banning children in cars altogether?
The report also found that two-thirds of those surveyd said they had rowed with their misbehaving children while driving. Some 43 per cent claimed to have had toys thrown at them.
However, the report did not quantify the immense skills developed by parents of screaming children in the back. Take Power Rangers for example - how many non-parent motorists can say with certainty they could pick up a fallen Power Ranger in the back while driving in front? How many have the extremely useful skill of withdrawing a banana from a bag on the passenger seat, peeling it, handing it to a customer in the back, picking up the the bit that falls on the cream interior and then disposing of the skin in the side bin on the drivers door - all executed while changing gears, sneezing, talking on the phone, shouting at other motorists, avoiding pesky pedestrians and cyclists, and adjusting the air conditioning?