The BMW M5 CS is my favorite BMW of the past two decades, at least. It might just be the best BMW M5 of all time and it’s certainly the best sedan I’ve ever driven. It’s nearly perfect, with its only flaws being cosmetic interior ones and a semi-lame exhaust. So when I see that G-Power took one of the very few M5 CS examples in existence and tuned it, my eyes start to twitch and my skin starts to crawl. You shouldn’t mess with perfection. Although, even I will admit this G-Power M5 CS does improve upon the car in one way—its noise.

In this new video from AutoTopNL, we get to see a G-Power-tuned BMW M5 CS that supposedly makes 820 horsepower. I’ve driven the 626 horsepower M5 CS and one thing it absolutely did not need was more power. With almost 200 horsepower more, the M5 CS is a handful, easily drifting across public roads in this new video. G-Power took an already brutally fast car and made it even more extreme. The M5 CS is such a perfectly tuned weapon, I’m not sure adding more power will do anything but make it worse.

BMW M5 CS Test Drive 13 of 40 830x467

Admittedly, I don’t think anything was done to the suspension or steering (which would be a sin), but upsetting the power balance probably makes the car feel a bit too spikey. However, I will say that the exhaust note is much improved on this G-Power car. The M5 CS’ only real flaw is its exhaust noise, which is as boring as all S63-powered BMWs. The G-Power exhaust (I assume it’s their own exhaust, the video doesn’t say) sounds far better than the stock car’s. Because I’m a boring old man, I actually prefer the way it sounds with the valves closed—with valves open, there’s too much manufactured exhaust flatulence and it sounds dumb.

If I were to own a BMW M5 CS, I’d kill anyone who dared to modify 99-percent of it. Although, this video does prove that an exhaust upgrade is quite welcome.