Some owners of the E60/E61 BMW M5 aren’t willing to swap their rides for the latest version – and for a good reason, as they pack a naturally aspirated 5.0-liter V10 engine.

The stock output is 507PS (500hp) and 520Nm (384lb-ft) of torque, or less than 100PS (99hp) shy off the new model, which has two less cylinders. Not bad for a car that dates back to the previous decade.

But what if one needs more power from their trusty M5? Well, then they’ll have to turn to a tuner. In the case of G-Power’s supercharger, the output grows to a staggering 700PS (690hp) and 680Nm (502lb-ft) of torque.

The upgrade fits both the E60 and E61 saloon and Touring (estate) versions of the M5, as well as the second-gen M6. The latter was around from 2006 to 2010 and uses the same 5.0-liter V10 as the M5.

G-Power doesn’t say how fast their tuned E61 BMW M5 is, but the upgrade costs a steep €16,838.50 (equal to $20,900), and that’s without installation. This can be joined by other aftermarket parts, such as a new exhaust manifold and sport catalysts.

Browsing through their offerings reveals yet another compressor system for the BMW M5/M6, which raises output to 1,001PS (987hp) and costs €69,500 ($86,268). That’s about €10,000 ($12,413) more than a new M2 Coupe in Germany, but hey, it boasts the exact same output as the first Bugatti Veyron!