I’d never heard of the disease. Pilonidal Sinus is called the Jeep Disease or Jeep Seat (and probably others). I’ve taken the following paragraphs below from a Canadian link:
http://www.canada.com/topics/bodyandhealth/men/story.html?id=ac51b5e9-23a4-42c9-be8c-19a55aa0a8dc

“Pilonidal sinus most commonly affects that area known affectionately as the butt crack, though it can show up in the belly button, genital region, even between the fingers. Basically, it’s an infected area under the skin, frequently containing a tuft of hair. Think of it as a nasty, hairy, painful tunnel and you wouldn’t be far wrong. Often it starts with ingrown hairs, although new evidence shows that’s not always the case. There’s a genetic component; it tends to run in families, and it’s more prevalent among hairy guys, and those who sweat a lot.

According to a document co-authored by Prof. Keith Harding, the head of surgery at the University of Wales, the condition is 10 times more common in adult males than in adult females.

Harding notes that it was called “jeep disease” in the Second World War since it affected many soldiers who sat for long periods on hard seats.”

A couple more links:
From Wikipedia: http://en.wikipedia.org/wiki/Pilonidal_cyst
From the UK: http://www.wounds-uk.com/journal-articles/pilonidal-sinus-jeeps-disease-an-improved-model-of-care

John forwarded this meme.

A reader forwarded these photos taken in northern Canada. Rather than recycled or otherwise utilized, the parts and vehicles were bulldozed over the edge of a hill. As you can see, amongst the debris are some jeeps.

Mark and his wife Barbara attended a local British Car Club show last weekend. Though theirs was the only jeep, they still enjoyed themselves.

He writes, “Last Saturday, My wife & I attended an annual British car show in Newburgh, Indiana, along the Ohio River. The group is the Southern Indiana Region British Car Club (Sir Brit). Probably around 40 cars there. There were mostly MGs, Triumphs, etc. but what I thought would be of interest on ewillys is a 1967 Land Rover.

It was a lot of fun to take our 1945? CJ2A there and park it near the show cars. Our CJ2A drew a lot of attention. I’ve attached pictures of my lovely wife (Barbara) modeling with our CJ2A, a few of a Land Rover, and several of a late 40s MG and a late 50s Triumph.”