Overview

On the day most people are waving their children off to school for their first experience of playground politics I'm off to AMG's Driving Academy. I wouldn't usually be concerned, but with the SLS AMG GT3 being my training car I'm peeing my pants.

'Nicht gut'. Not something you want to hear when a woman's just pulled a heart monitor off your chest and looked at the screen. I'm trying my best to remain calm as I'm put through a physical examination by the medics prior to being allowed anywhere near the track. Having just been given a polite reminder to consider laying off the pies by her colleague after a BMI check I'm worried about my ticker. Thankfully it's the connection, so I have to sit for another two minutes in silence as my heart's monitored.

It's beating pretty quickly, but then I've just been given a walk around the car I'm due to be driving shortly. A Mercedes-Benz SLS AMG GT3. Now, I'm lucky enough to be fairly familiar with the SLS road car, but the GT3 is a different proposition altogether. It's the car that Mercedes-Benz goes racing with. Proper race teams pay over £250,000 for these, then rock up at Spa, the Nurburgring and the likes, pop a handy driver in them and collect podiums. Honestly, one of the cars we're using is just back from a third position at the Spa 24 hours.

Serious kit, which warrants the serious medical. Thankfully I pass, though I'll be laying off the pudding at lunchtime. That'll help with the seat fitting too, where I squeeze myself into a foam chair to limit my movement when in the GT3. Then it's theory time, where chief instructor Reinhold Renger takes us through the basics of the SLS GT3. I'll have an instructor sitting beside me, so I'm not overly concerned about the 39 buttons he lists - though do take note that no.13 is to be avoided as it blows the hinges on the doors should the car roll over.

Not that I'm intending on rolling over £250,000 of carbon-fibre and aluminium race car, not least as there's a large waiver if I damage it. I'd have a job too, as the Groß-Dölln driving centre doesn't have much to hit. Built by the Russians during the Cold War there are four kilometres of 1.5-metre deep concrete making up a runway, with access roads of similar length and width. The perfect place for giving a hapless hack the opportunity to drive a current, highly competitive racing car, then.

As with all racers there's a knack to getting in. It's feet first in the SLS GT3, the exertion required making me thankful for the time it takes my instructor, the affable Patrick Simon, to get in. When the technician plugs in my radio I sound like a phone stalker, my heavy breathing thankfully calming before Patrick plugs his system in. Radio check, then the SLS fires up, Simon taking over as he presses the main systems button, then the ignition switch while I check the paddle-shifted transmission is in neutral. The start button is then pressed and the SLS GT3 vibrates as the engine management blips the accelerator to settle into a lumpy idle. There's a clutch for first, and thankfully I don't stall it as it judders away from the pit.

Racing cars don't like going slow, the GT3 shuffling down the narrow pit lane with me feathering the clutch. Quick pull of the right hand paddle and second gear settles it. It's a short pit-lane, and as I select second I shift my left foot from the clutch to the brake, where it'll be doing all the work. Earlier I'd had an opportunity to try the GT3 on a long straight running up and down, teaching my left leg to brake. It's little different to stabbing the clutch, except there's less give, though however hard you push the pedal the SLS just does what it's told and bins masses of speed.

That's the key difference between it and its road-based relatives. Having had a few sighting laps around the tricky - but enjoyable - track in the standard SLS it's the brakes that really shock. That and the grip, which, even on hard compound and cut intermediate tyres, is phenomenal. The performance, though amazing, doesn't shock like it does in the road car. It's all about the brakes. Nothing prepares you for the way they brutally wash off speed. I'm thankful for those tight belts, which don't feel so tight when you're hanging from them as you trail brake into a corner.

Patrick's the perfect instructor, giving small pointers without bamboozling and distracting my attention from the 550bhp on tap (actually lower than the road car thanks to air restrictors). He's quiet most of the time, allowing me to settle into a rhythm with the car and enjoy its incredible ability. It's surprisingly easy, but then I'm guessing I'm barely scratching at the surface of its ability.

Apparently not: one of my fastest laps was in my first seven-lap session. Certainly there are improvements to be made; I'm too early on the accelerator though bends and I need to time some of my down-shifts better, but there's some ability there. I get the opportunity to improve too, as two more track sessions see me steadily get faster and the instructions from my right become fewer. Telemetry data allows me to analyse laps between sessions, and convince myself I could have been a contender.

That's brought sharply into focus after 24 laps (not 24 hours), though. It's killed me; I'm exhausted. Easy as the GT3 proves, it's still an incredibly taxing experience mentally and physically. It's one you too could experience though, assuming you've €4,500 (less than £4,000) to spend... That might sound expensive, but it's a tiny fraction of what it'd cost to have a race team run you in one on a test day. Just be sure you're fit to make the most of it...