Comedy is subjective, but The 2 Johnnies prove sometimes it's also just plain subpar

Take Benny Hill's infamous "girls are like pianos" one-liner, which was probably as humorous in 1970 as it is today.

Or the more recent Holocaust ­routine delivered by Jimmy Carr, who apparently forgot the second part of the adage that you can joke about anything once it's funny.

Tacky bumper stickers may seem like safer territory than, say, genocide, but as The 2 Johnnies found out, if it doesn't have them rolling in the aisles, it can be just as much of a car crash.

Only three days after bursting onto 2FM with their new drivetime show, presenters Johnny O'Brien and Johnny Smacks hit the skids over a promo video taken from their hugely popular podcast, which saw them read out some of the drivel that revheads across the country have plastered on their motors.

Now, you could argue that all bumper stickers - ranging from "condoms prevent minivans" to 'I'm so gay I can't even drive straight" - are about as amusing as whiplash.

But I'd rather be rear-ended by a Russian tank than stick any of the "virulently sexist" slogans in question - according to TD Holly Cairns - including 'Tyres are like women, no good unless they are squealin'' and 'She's not a princess, she's a slut', on the back of my trusty i30.

Amid much bigger issues in the world, incredibly, while the Russian Ambassador to Ireland remained in situ in nearby D6, Johnny B and Johnny Smacks - as they're better known to their worldwide army of fans - on Thursday found themselves out in the cold, and off the air, while RTÉ bosses "reviewed the matter".

Sandwiched between the recent RTÉ Investigates documentary ­Domestic Violence - A Year of Crisis and the upcoming two-part ­series ­Ireland's Dirty Laundry, in the ­context of the broader societal ­conversation about the relationship between everyday sexism and violence against women, the 'Irish Car Stickers' segment did seem like a particularly tone-deaf way to drum up support for the new show, even if it's clear from the clip that the lads found them "scandalous".

The biggest laugh of all, however, is the station's subsequent defence: "RTÉ believes in dignity and respect and does not tolerate material or attitudes of this nature."

In the race to stop haemorrhaging listeners, it's like the bosses didn't even bother tuning into the comedy podcast, beloved of college-going culchies, before launching the Tipperary hosts on an urban 3-6pm audience whose bumper stickers are more likely to read 'Baby on board' than 'Workin' the land and droppin' the hand' - another particularly lame example cited by the duo.

If they had, incidentally, they'd also hear 30-year-old Johnny Smacks and 35-year-old Johnny B discussing issues like consent and safe sex with their one million listeners a month.

Ricky Gervais, a comedian who has sailed close to the wind, recently urged people to stop moaning "you can't joke about anything anymore".

"You can joke about whatever the fuck you like," he said of the backlash against 'cancel culture'. "Some people won't like it and they will tell you they don't like it. And then it's up to you whether you give a fuck or not. And so on. It's a good system."

An even better system for the national broadcaster, which has done its reputation as the place where Irish comedy goes to die no favours this week, would be knowing its audience - and gags that are occasionally funny.