| Feature Drive | Oaxaca, Mexico | Mercedes-Benz SLS AMG |

Two hundred and sixty testing miles of driving is ahead of me. As is a Mexican Federal Police Officer in a Dodge Charger with his blues and twos on to clear the road. I'm in a Mercedes-Benz SLS AMG; a car we know is not short of pace, going on previous experience. Motoring nirvana? Absolutely.

I'm buzzing with excitement as we drive through the bustling streets of Oaxaca, Mexico. We're heading out onto the roads that once made up part of the Carrera Panamericana - Mexico's answer to the Mille Miglia, only quite a bit more unhinged and with cacti lining the roads.

The 260-mile section we're covering is a mere fraction of the entire 2,050-mile route, which ran five times in the 1950s before being cancelled in 1955 due to safety concerns. It was initiated to publicise the new Panamerican highway through Mexico, and was thought to be the most dangerous race in the world. Looking at the roads, I don't doubt that.

We're here with Mercedes to drive part of the course, in a car that can trace its roots back to the 300 SL prototype that took a one-two in 1952. A bit of reading before heading out underlines just how gruelling the original races were. A chat with one of the original drivers, John Fitch, confirms this. The 'Benz of Karl Kling and Hans Klenk took the win in '52 despite a vulture hitting the windscreen at 120mph on one of the opening stages. That explains the bars on the windows of the original race car that's at the start in Oaxaca. I've no such bars, and really I don't expect to be reaching 120mph, either.

How wrong was I? Heading out of the city, the Police are intent on getting us going as quickly as possible: speeds of 110-, 120-, 130mph and above were regularly attained on a run down the motorway towards Route 125. Fortunately the vultures are flying high, and the roads are clear, but even maintaining such high speeds in a modern car like the SLS on less than perfect roads underlines just how hardcore the guys in the 1950s were. They achieved much the same speeds at sustained pace, without modern tyres, brakes or suspension. Or ventilation. In a quick 15-minute run in the passenger seat of one of the '52 300 SLs it's apparent just how uncomfortable it must have been. I'm exhausted just in the passenger seat, sweat dripping down my back and my ears ringing with the noise of the 3.0-litre six-cylinder being wrung out up a winding, switchback section of the route. And they did this for 2,050 miles. Madness.

Back in the SLS it's almost impossible to truly comprehend the challenge that the races in the fifties must have represented. The SLS has masses of grip, huge performance, an easy paddle-shifted automatic transmission and creature comforts like automatic climate control, electric seats and a fantastic stereo. The 50's race cars had none of this, except huge performance - for their time.

John Fitch, driver of the third and disqualified 300 SL, describes the event as tortuous, and particularly hard on tyres. The racers carried two spares to cope with the numerous blow outs. Fitch admits that he had one on every stage, except for the last one, where he somehow sustained a 135mph average.

The 92 year-old is frail, but there's an intensity in his eyes when he describes a stage that's clearly lived with him ever since. A moment of madness, or one of heroic, devil-may-care focus, the thought of that 135mph average rears its head as I sustain 140mph with the SLS's steering wheel bucking and weaving in my hands on the far from perfect two-lane tarmac surface.

With its 6.2-litre V8 engine developing 563bhp - nearly four times that of the 50's 300 SL - the SLS doesn't have any trouble getting up to the high velocities that the 50's drivers strived for. My bravery levels aren't as high as theirs though; despite plenty of grip, the worry of local traffic, donkeys, goats and vultures - of course - and not to mention people is enough to reign in my enthusiasm.

But we're making cracking pace; it's just there are other people to consider, the route taking in plenty of towns and villages. Even if I wanted to be irresponsible here it wouldn't be possible, as the Mexican authorities have taken the idea of sleeping policemen to the maximum. They call them 'topes', these fattest of sleeping policemen sometimes but not always highlighted by a sign and arrow stating 'Reductor'. They're more often than not signalled by expensive-sounding scraping from the SLS's underside - as even crawling pace and odd angles of approach aren't enough to prevent the floor making contact.

Out of the towns the roads are among the best I've ever driven. Long straights though valleys are punctuated by technical climbs and descents that flick and weave around the contours of the mountainous landscape. The scenery, when it's not flashing by, is stunning, while the poverty on display disturbing. It feels slightly uneasy driving by pick-ups laden with entire families, or past tumble-down breeze block shelters that the locals call home in such a conspicuously expensive car.

The locals love it though, our arrival signalled by the blaring exhaust note and high-revving phonics from the V8. Everyone stops and stares, with the SLS attracting admiration rather than jealously. As the route becomes less and less rural and heads towards the massive conurbation of Puebla the traffic gets busier and the opportunities to use the SLS's performance lessens.

There's one last stretch where a clear dual carriageway allows me to give the SLS its head. Passing one of the police cars supporting us at 130mph is not something I'll ever forget, nor is the limiter cutting in at 155mph. The SLS is apparently capable of 197mph. But not here in Mexico, where it seems the AMG people have limited it. One thing that's for sure, limits weren't something the Carrera Panamericana's original racers were every worried about. I think in my case though it wasn't such a bad idea.