In 1955, Sir Stirling Moss, in a Mercedes Benz 300SLR, covered the roughly 1,000 miles from Brescia in the Italian countryside to Rome and back in a record breaking 10 hours, 7 minutes, and 48 seconds – at an average speed of almost 100 miles an hour. This was a time when gentleman drivers would often lay down their lives for their craft. It was a time of stunning aerodynamic designs, and breakthrough engineering. And that’s why this incredible feat at the legendary 1955 Mille Miglia road race still captures peoples’ imagination even today.

To honour this achievement, at the Detroit Auto Show, McLaren and Mercedes will unveil the final example of their modern interpretation of the SLR – the new SLR Stirling Moss. The SLR has been produced is various forms over the past decade, and this is its swan song before production ends in May 2009 – with the exception of 75 examples of the SLR Stirling Moss, which will be built from June to December 2009.

While the new SLR Stirling Moss isn’t quite as stunning as the original, it’s certainly a very striking design. Beauty may be in the eye of the beholder, but one thing’s for certain, it’ll definitely be one of the most unique pieces of machinery out on the roads – especially since it has no roof and windscreen. And if you do happen to see one, it’ll likely be the rear end as it flashes past, which features prominent roll hoops on top and a massive underbody diffuser at the bottom. The long carbon fibre bonnet encases the same supercharged V8 that did duty in the last special edition SLR – the ‘SLR 722’ (which also harks back to the 1955 Mille Miglia, since that was the number on Stirling Moss’s car – corresponding to his start time of 7:22am). The hand crafted power unit produces 650 horsepower, and propels the SLR Stirling Moss to 100km/h in under 3.5 seconds, and all the way to a top speed of 350km/h.

Oh, and one last thing, even if you do happen to have a million dollars lying around, you won’t be able to buy one unless you already have an SLR parked in your garage. Well, if you’re dreaming...

In keeping with BMW’s new design language, which is intentionally bold and polarizing, the Z4’s face is aggressive with wide kidney grilles up front – it looks as though it could stare down much larger machinery on the street. On the inside as well, the Z4’s cabin looks to be very well executed indeed. It features BMW’s latest generation i-Drive, which is easier to use than previous versions.

The Z4 is also the first BMW to feature a retractable hard top, which can be raised or lowered in 20 seconds. And while the Z4 is larger than its predecessor, the front subframe and suspension are made largely from aluminum to reduce weight.

When it goes on sale in Europe in May 2009, the Z4 will come with the option of three 6-cylinder power units. The sDrive23i will be powered by a 2.5 liter straight-six producing 204 horsepower. The sDrive30i will have a 3.0 liter straight-six that produces 258 horsepower, and accelerates to 100km/h in 5.8 seconds. Both these models come with either a 6-speed manual or automatic transmission. The top of the line Z4, the sDrive35i, gets BMW’s ‘Engine of the Year’ winning 3.0 liter, 6 cylinder, twin-turbo, direct-injection masterpiece. It produces 306 horsepower and propels the car to 100km/h in true sports car fashion – taking 5.2 seconds with a manual transmission, and 5.1 seconds with the optional 7-speed dual-clutch gearbox.