Posaidon's 853 hp AMG 63 Mercedes There are two things you need to know about the guys behind Posaidon. First, they're not great at spelling mythical Greek deities. Second, they're definitely good about getting power from a Mercedes. Their newest package for the AMG 63 bumps horsepower to 853, which results in a top speed of 214 mph. Not bad for a four door.
Mansory's 650 hp Rolls-Royce Ghost Series II Mansory is sometimes known for going a little overboard with their designs. Look at the lines on this take of Rolls-Royce's newest palace and you'll find a fairly restrained approach...at least on the surface. Lift the "bonnet"—hey, it's English—and the power's been bumped to 652 hp. That's definitely enough to get home in time to take afternoon tea.
DMC's 660 HP McLaren MP4-12C MSO So, you take a not-bland McLaren, run it through McLaren's Special Operations division to make it even sweeter, then send it to the German carbon fiber-meisters at DMC. What do you get? A car with subtle tweaks at the front and side, a double wing in back, an interior full of whatever material you can think of, and an engine that's been bumped to 660 hp. That'll do.
Reiter's Gallardo Extenso R-EX By far the most performance driven of the lot is Reiter's new take on the old Lamborghini Gallardo. It's intended for racing, and the rear wheels have been pushed out by over five inches to help improve the car's handling tremendously. If you're serious about going fast, and racing at a semi-pro level, this is a good starting point.
Techart's 911 Targa Techart has a long history of making Porsche's even sportier, so for the 911 Targa, they've just dropped a heap of new parts that transform not just the front and rear with spoilers and a diffuser. To make sure the first thing you do with your new spoiler isn't destroying it on a speed bump, they've developed a new system that lifts the nose by almost two extra inches over stock.