"You stupid black woman": My repulsive encounter in a suburban car park.

The scene was perfectly predictable. Mid morning, mid week in the carpark of a small shopping centre near our house, a snapshot of suburban life. A sunny and slow Sydney day.

I’d loaded the groceries in, clicked my baby into her carseat and was in the process of collapsing the pram to load in the boot, when I noticed a woman waiting for my park. The driver of the shiny black BMW was in her fifties, possibly her sixties, with immaculately coiffed blonde hair and a string of pearls around her neck. She looked like a genteel cliche.

She was anything but.

“Go around me you stupid black woman” I heard. I was so shocked, I immediately turned around. These ugly words had indeed been spat out of the mouth of the BMW driver. There was a scowl on her face as she signalled to the woman, waiting perfectly patiently, behind her.

I heard it because the window of her BMW was down and I was standing less than a metre from her car.

I am quite sure the second driver, a middle aged Asian woman, didn't hear it, small mercy, because her car windows were closed and she seemed completely non-plussed, chatting to the teenager sitting in her passenger seat.

My heart was racing. I was shocked and disgusted. Had I heard right? Surely not, I tried to convince myself.

But I did hear right and I was at a loss as to what to do.

Confront her? Report her? To whom?

It was repulsive to encounter: pure unadulterated racism. The car park wasn't busy, the waiting driver wasn't on her horn, there was no obvious trigger for the outburst.

At a loss, I glared at her before closing the boot and driving away.

I spent the rest of the day trying to process it. Who speaks like that? The contrast between this woman's perfectly polished exterior and the vulgar interior that her language revealed was stark.

Watch: Stan Grant on racism in Australia. Post continues after video.

I am not naive. I didn’t need to witness this episode to realise that racism in Australia is alive and well. I know it is. But I hadn’t ever witnessed it quite like this.

It was so casual and so ugly and it made my blood run hot and cold.

Hot in anger: Who does she think she is? What causes a person to speak to a stranger like that? Cold in fear: this is the picture of bigotry and it is close to home. Literally.

If this woman, in a quiet old Sydney suburb, seemingly unaffected by life’s cruelest vicissitudes, has that vitriol to discharge at the ready, to a perfect stranger, with no obvious trigger, what hope is there?

Had I not been fumbling to collapse the pram her vile intolerance would have remained invisible to me. But it would still exist. It does exist. It’s simmering barely beneath the surface and it’s frightening.

Particularly now. In the aftermath of 53 innocent men and women being gunned down in Orlando. In the days following a virtuous, young and committed British MP and mum being shot and stabbed to death in public. At a time when Donald Trump is likely to be the Republican’s presidential nominee. These things compounded my despair in the carpark.

In some ways they are worlds apart, but in others they’re not. Intolerance and bigotry are the common threads that weave between these people and incidents and we know, all too well, the damage they’re capable of inflicting.

So, yes, I witnessed an ugly display from just one woman but in the week that was it felt much bigger than that. It felt horribly prescient and symbolic.

The question I had - then and now - is the same. What to do?