RM Sotheby's is full of four-wheelers you'd lose a finger for, but if we need to pick the eleven that would make your hair stand on end the most, these would be the contest winners:
2014 Mercedes-Benz SLS AMG Black Series
The SLS Black was AMG's answer to the Lamborghini Gallardo LP570-4 Superleggera and the Ferrari 458 Speciale. With a 622 horsepower V8 that sounds like the rumble of a warplane and a human's worth of weight shed from its body, it certainly wasn't for the faint hearted. If you think the standard SLS was hard on your back, think again.
1974 BMW 2002 Tii Alpina A4S
Sure, the 2002 Turbo was a thing. A fast thing with the right stripes. But if you wanted the wildest naturally-aspirated BMW New Class, you had to buy a 2002 Tii. Except that you could go even further, opting for an Alpina and then enjoy 195 horses in a rear-wheel drive BMW that weighs nothing. It only cost twice as much as a standard 2002, but look at that investment today!
1998 Ruf CTR2 Sport
Oh, it's a road-going Porsche from the late nineties! What's hardcore about that? Well, it's a RUF, and when RUF paints a 911 yellow, things can get a bit out of hand. This particular CTR2 Sport is one of just 15 ever made, and it packs a 580 horsepower twin-turbo flat six, all-wheel drive, a six-speed manual and carbon-ceramic brakes. Don't you need something that can eat a GT2 RS for breakfast?
2008 Ferrari F430 GTC
While there wasn't much to love about the standard F430, one easy fix was to gut it and turn it into something that can win the 2008 24 Hours of Spa like this one did before retiring the following year. The GTC's engine might be smaller due to FIA regulations, but it has 450 violent horses running through its rear via a six-speed sequential gearbox. And talk about aging well!
1991 Porsche 911 Carrera Cup
Look what a cute little 964! I'm surprised Singer didn't transform this one into a $600,000 masterpiece yet! Well, they can't touch this, because this Maritime Blue wonder is worth just as much, if not more. One of only 270 Carrera Cup cars produced, this 1991 example is a three-time Nürburgring 24 Hour participant with its original air-cooled engine tuned to produce 260 horsepower. It's complete with a five-speed manual and adjustable anti-roll bars, as it should be.
1954 OSCA MT4 1500 by Frua
Based on my visits to Goodwood, I can tell you that these fifties race cars can't really go quickly in a straight line. That's because they have relatively torquey engines sending way too much for the pizza cutter tires to handle. OSCA was founded by the Maserati brothers after they sold their company to industrialist Adolfo Orsi, and this Maserati Tipo 4-based car is a combination of a 135 horsepower four-cylinder and four-wheel drum brakes. You'll need driving gloves.
2010 Porsche 911 GT3 RSR
Looking at how clean the lines are on this white GT3 RSR is the best therapy I can think of. This 911 is one of perhaps two RSR examples that were built in 2010 with the powerful 4.0 M97/81 engine. The flat-six produces 455 horses and propelled this Porsche to P1 at the 24 Hours of Spa and P3 in class at the 2010 24 Hours of Le Mans. It never incurred any damage during its racing career.
1982 Renault 5 Turbo Group B
Looking for a car that can do a full 360-degree turn on a tight two lane road without ever touching the grass? Look no further! This ex-Renault works car has an extremely short wheelbase at 95.6 inches and 255 horsepower in mild tune from a 1.4 with a big turbo. Upgraded from WRC to Group B in its day, it's now for sale with a spares package and its original homologation papers for Group 4 and Group B.
1934 Alfa Romeo Tipo B P3
No seat belts, and you're probably better off without them sitting behind a DOHC straight-eight that throws 255 horsepower at a live rear axle and four-wheel mechanical drum brakes. This car was campaigned by Scuderia Ferrari during the 1934 and 1935 Grand Prix seasons, which I guess is enough said.
1970 Porsche 917/10 Prototype
Are you ready for the fury of Porsche Chassis no. 917/10-001? If even for a brief second, you thought "yes" was the answer to this question regarding Porsche's first 917 Can Am Spyder, you are definitely not ready. Five liters and more than 600 air-cooled horses, the chance to grab the only 917 of all variants with chassis number '001' in private hands. Scary, but very rewarding, no doubt.
1956 Inter 175A Berline
Not hardcore, you say? Just imagine looking at your average suburban SUV's grille through that tiny mirror! A one-cylinder 175 cc engine's eight horsepower moving you towards a destination you can only hope to reach. This is one of the estimated 30 survivors, although none of these French microcars are completely identical.