Live from the Dubai 24 Hour Part IV

Samir Sharma is a curious specimen. He's a race marshal we found huddled around a tea urn on a frozen turn 14 at 4:00am. After asking if he'd rather not be doing something - anything - else, he paused for a few careful seconds and replied: "No. This is perfect."

He's been part of the army of eyes recruited (for no pay) to oversee proceedings at the D24 for the past three years: "Every time you come to this race you watch the drivers again and again and learn how to control a car safely. This is the most useful information you can have as a driver."

Coming back next year? "Of course."

Unlike F1, you don't get live telemetry in GT racing - information about fluid levels and temperature's stored on board, but you're only allowed to liberate the information when the car's stopped.

The screens you see the team bosses staring at are just elaborate, bewilderingly complex timing boards.

"There are two schools of thought when it comes to shaving tyres," says Nissan team boss, Bob Nevill. "Some think it's a great idea, I don't.

"We always thought that introducing localised, intense heat to a tyre could compromise it - they weren't designed to take that amount of heat in such a small area."

But what about the compounds? Entrants of endurance races sponsored by tyre companies (nearly all of them) are all assigned the same rubber - soft day tyres and harder night tyres, in this case.

But Bob's got his own methods: "you play around with the tyre pressures and wing angles to adjust grip levels."

Jann Mardenborough, the UK driver steering Nissan's GT Academy 370Z, talked us through the challenges of night driving.

"You need to find visual markers for braking points - on turn one, for example, I clock the reflective post next to the marshal and know that it's time to slow down. But, with the other headlights in the night, it can be a lot more difficult to spot them."

Banana enthusiast and Thoroughly Nice Chap, Martin Baerschmidt, put the demands of endurance racing into perspective for us.

"It's like three race seasons in a day. Usually, you're racing for eight hours per championship. This is one big, long hit. Lot of fun, though."

And this is his car - #119 Aston Martin Vantage N24 GT4.

Braking gets increasingly brave as sunrise - and the race's culminating laps - draws nearer.

This is spare bottom for GC Automobile's marvelous - but dead - V8-powered BMW 1-series racers.

These are the only two fans left at 4:30am. The very definition of hardcore.

Otherwise it's utterly, eerily deserted.

As in really, utterly, eerily deserted...

A moment's sleep's snatched at every opportunity, regardless of the bed's integrity - how this man can get any shut-eye so close to earfuls of engine racket we don't know

The Trofeo Lamborghini enjoyed a lot of time on pole position through the night, but subsequently dropped down to eighth.

PIT STOP! #888 R8 docks for a set of fresh rubber.

There's a little Suzuki Swift in here somewhere - unbelievably, it's still powering through.

Optimum Motorsport's Ginetta 3.5-litre six-pot G50 - and its all-Brit driver lineup - puts in sterling performance, clinging on to 18th position by morning.

The solitary survivor from GC Automobile's crop of Very Insane Racers battles forth, currently holding on to 24th position overall.

Battle scars. This is how our brains feel.

If we've not collapsed from exhaustion, we'll see you in the morning - clock in to see how the cars have held up through the night.