What to do when you've got a 600 horsepower BMW Z4 that loves to smoke its back tires on your hands? The only logical answer is to take it to Germany's limitless Autobahn network and allow it to run free. That's exactly what the AutoTopNL did and, boy, is it a joy to watch. Just to refresh your memory before we delve deeper into this crazy build: never did the E85-generation Z4 come with anything bigger than the 3.2-liter S54 inline-six from the factory. Yep, we don't quite know how the E60/E63-era V-10 fit in there either but here it goes.

How to take all the dull out of a '00s BMW Z4? Throw a V-10 in it

The first-generation BMW Z4 was introduced in 2002 at the Paris Auto Show as the replacement for the Z3. The North American version was in showrooms by November of that year and, at first, you could choose either the 2.5-liter N52 inline-six or the 3.0-liter M54 six-banger. The latter made 228 horsepower and 221 pound-feet of torque, enough to power the 3,000-pound roadster from naught to 60 mph in just under six seconds.

If the open-top Z4 simply wasn't your thing you were, for a few years, out of luck as the Z4 Coupe was first previewed in concept form in 2004 before being introduced at the 2006 New York Auto Show. The Tomasz Sycha-penned fastback coupe differed visibly from its roadster brother while also being more practical (offering up to 10.1 cubic feet of trunk space) and stiffer as you'd expect from a car with a fixed roof.

BMW was kind enough to offer us at the time an M version that effectively replaced the venerable Z3 M Coupe aka the Clownshoe.While the roadster version was slightly lighter than the coupe, both cars would do 0-60 mph in 4.8 seconds en route to an electronically-limited top speed of 155 mph.

The S54 powerplant, which was taken straight from the E46-generation M3, put out only 330 horsepower in US-bound models. To cope with the added oomph compared to the non-M models, the range-topping Z4s featured a wider track, revised front suspension and steering geometry (with hydraulic power steering, and wider tires. The M cars were only available with a six-speed manual by ZF.

The Z4 you'll see in the video isn't an M car but, thanks to an M5 E60-sourced V-10 engine under the hood, it actually makes more power than the M cars and, believe it or not, more than even the race-bred Z4 M GT that was raced throughout the noughties in the Britcar Series in the UK, as well as Super Taikyu and Super GT in Japan. Those cars made no more than 400 ponies.

If you know Manhart, you'll know this is a Manhart build just by looking at it: the black-with-gold paint job and the 19-inch black wheels are clear giveaways and that hardtop suggests this car would probably rip its soft-top to shreds going flat out.

To keep everything steady, Manhart fitted the Z4 with 14.9-inch front rotors with six-piston calipers from Brembo while the brakes in the back ar from an M6. Bilstein supplies the coilovers and the stainless steel exhaust is a Manhart in-house product. With over 600 horsepower and 472 pound-feet of torque at the crank, this Z4 is sure to light the rear tires, especially as it goes into the red really high, at 8,200 rpm. The diff in the back is from an M5 E60 too and the transmission that dispatches all the power from the engine to the back wheels is from an M3 E92 and it's fitted with a "racing clutch" according to AutoTopNL. You already know the results of this Frankenstein-esque job must be out of this world so just do yourself a favor and spend 11-odd minutes watching this video. You and your ears will love it!