Jerry Seinfeld is auctioning off $10 million of incredible Porsches

The 1955 Porsche 550 Spyder. Estimated price: $5 to 6 million

The car is said to be entirely un-restored and original ...

... and has only 10,300 miles on the odometer.

But the model comes with a rather infamous reputation: actor James Dean was killed after crashing his own 550 Spyder in 1955.

The 1958 Porsche 356A Carrera Speedster GS/GT ...

... one of only 151 Carrera speedsters produced.

The car has recently been given an award-winning restoration.

Estimated price: $2 to 2.5 million.

Here's the 1974 Porsche 911 Carrera IROC RSR.

The engine is in the back, where any Porsche enthusiast will insist it should be.

"IROC" stands for the International Race of Champions, a sort of all-star car race that featured some of the world's best drivers and that ran from the 1970s unevenly through to the mid-2000s. This one was driven by Peter Revson.

And the IROC RSR can be yours for an estimated $1.2 to 1.5 million.

These stunning cars are rumored to be only a small fraction of Seinfeld's collection. He says that he's selling so that other Porsche lovers can enjoy these machines.