There’s nothing funny about this Porsche.

A 1971 911S modified by Ruf Automobile just sold for more than $650,000 on Bring a Trailer earlier this week. Any example of the iconic sports car that the German shop has worked on is noteworthy, but this particular example also belonged to one of the famous Porsche collectors of them all, Jerry Seinfeld.

Most of us would be more than happy with any first-generation 911, but not Seinfeld. As the comedian has shown repeatedly over the years, he’s only interested in the very best from the German marque, like the 917K he turned down $25 million for earlier this year (and sold for an undisclosed amount weeks later). So, when he acquired this 911S in 2008, he immediately had it shipped to Pfaffenhausen for some work. Three long years later, Ruf, which is renowned for the craftsmanship of its high-performance builds, shipped the coupe back across the Atlantic, with more power than before.

The big story here, as with all the shop’s builds, is the mechanical changes that have been made to the car. The car’s original rear-mounted 2.2-liter six-cylinder has been swapped out for a Ruf-built, twin-plug 3.4-liter flat-six with individual throttle bodies and electronic fuel injection. The new mill, which is mated to a six-speed manual transaxle gearbox, nearly doubles output from 177 hp to 340 hp. Ruf also reinforced the 911S’s chassis and equipped it with a Bilstein suspension, a G50 rear torsion tube, and 930 disc brakes. The slew of modifications should be in good shape, too, as the car has totaled just 2,300 miles since leaving Germany a second time.

The shop’s work wasn’t just limited to the mechanical side of things. It also equipped this longhood 911’s body with rear wheel arches, a new lighting package, and a sunroof, before repainting it in its original color of Gemini Blue Metallic. Inside the car, the rear bench has been ripped out so that reclining sport-style seats with Pepita inserts could be installed. The rest of the cabin looks almost identical to when the car was brand new, although the cockpit now features a Ruf-branded 10,000 rpm tachometer and 180 mph speedometer.

Unfortunately, Seinfeld’s Ruf-modified 911S has a new owner as of this week. The car sold for $657,000 on Thursday afternoon. That may not seem like much compared to some of the comedian’s other Porsches, but it represents one of the highest prices ever paid for a longhood 911 in the auction site’s history.

Click here for more photos of Jerry Seinfeld’s Ruf-Modified 1971 Porsche 911S.