“Just how badly do you treat your car?” asked the step-father of a 20 year old woman recently in an ‘ad’ for her somewhat neglected gold Peugeot 307 with 91,000 miles on the clock.

“I bet it isn’t as bad as this stinking, petri dish of McDonald’s infested filth my step-daughter calls her wheels” he went on in his unconventional sales pitch. “She has left her car in our carpark and I decided to give it away before it makes me throw up a bit in my mouth.”

The stepdaughter-shaming story about her dirty car got a lot of traction in the media – and also got the apparently irate dad a lot of free publicity for his motoring blog. We all love the shameful joy of a story about a filthy car. Or at least, a car that is filthier than ours.

John, 27, a plain-taking Yorkshireman has seen a lot of filthy cars in his time. “To be honest, some of them made that ‘stinking petri dish of McDonald’s infested filth’ sound quite appetising” he says. Almost nothing phases him. He has seen humanity in its true colours. And smelt it.

John you see works valeting traded-in cars at a busy used car dealership. He cares for cars that the previous owners have often fallen out of love with some time ago. His job is to make them look loved again – so someone else will fall for them. Sometimes Hercules had it easier with the Augean Stables.

The dirtiest, most unloved car he every had to clean was a Range Rover that belonged to a farmer. “It took four days to clean it,” he says matter-of-factly. “I had to start by shovelling the boot out”. For his troubles John found himself with a nasty case of ringworm.

Dirty cars can be a real health hazard as well as an aesthetic one. He once caught folliculitis from a Honda Civic. “The previous owner must have had the infection and not worn a shirt – we’d been having a heatwave. Fabric seats are very absorbent.”

The filthiest item he’s ever found? “Probably a pair of very heavily-soiled frilly pink nickers – stowed under the passenger seat of a Porsche Boxster.”

The strangest item? “One very worn fleshy beige high heel, under the passenger seat of Subaru Estate. You would think that the owner would’ve noticed it was missing!”

John finds lots of ladies’ collapsible brollies – a shelf on the wall of his corner of the garage sports three abandoned ones, just from that week. He also finds sunglassess. “People tend to come back for those.” Unlike, say, soiled frilly pink panties, then.

“Some of the things people left behind can be quite poignant” says JOhn showing me a Valentines card, still in the plastic wrapper, found in the glove compartment of a Ford Focus. “Did he/she forget to post it? Or was it an ‘emergency Valentines card’? We’ll never know”.

Does he finds many condoms? “Nope, never. But I did find lots of little see-through re-sealable plastic bags in a black C-Class Merc.” I wonder what they could have been used for?

Bad car odour is a perennial problem. Dog smell is almost impossible to get rid of: “You can try shampooing the carpets and seats but it just ends up smelling of wet dog, which is even worse of course.”

Mould smells the worst though. “Very difficult to get rid of it once it takes hold. Often find it in cars that have had kids in them. Milk spilt on fabric seats just seeps through the foam to the bottom where it festers and turns mouldy – then the mould grows through the seat and comes out the top. Once the spores spread it grows everywhere, on the window sills and door handles.”

Car owner’s strategies for dealing with pongs can be eccentric. “The Fiesta I cleaned this morning had four air Xmas tree fresheners hanging from the rear view mirror.” He reaches into the bin and shows me them: Artic Ice, Black Ice, Strawberry and New Car. All of them ancient and shrivelled.

The worst carpets to clean are the woolly ones in cheaper cars. “You can never get the rubbish out of them it just sticks. Cleanest cars tend to be Prestige cars like Mercs, BMWs, VWs, Jags. They also have better quality carpets, that are easier to clean.”

Is there a difference between men and women’s cars when it comes to vehicular hygiene? “Men’s cars tend to have more rubbish in them, but stuffed into door pockets and into the boot or glove compartment where they can’t be seen from outside. Women’s cars often have stuff just thrown everywhere and make-up on the controls.”

The cleanest car he’s seen? “An elderly couple brought in a Jag which was absolutely immaculate. That was the cleanest trade-in ever. They’d obviously ages valeting it inside and out.”

Such patience tends to be lacking in the younger generation. “Most just can’t wait to get rid of their old car once they’ve found a new one. And don’t seem at all embarrassed about the state they’re in when they hand them over. But I can’t complain too much as it keeps me in work!”

With that John gets back to combing out the curly carpet in a Fiat Punto that looks like its previous owner was a herd of especially inconsiderate wildebeest.

Originally appeared on LeasePlan blog.