Now that's a Porsche collection...

Albert Einstein once remarked that insanity is doing the same thing over and over again and expecting different results, clearly foreseeing the consequences of using an old Alfa Romeo on a daily basis. The late Matthew Drendel took this truism and applied it to his racing career.

This privateer racer started off his career in a Ferrari 355 Challenge, but after several "painful" losses, transferred his allegiances to a Porsche 911 GT3-R. Soon enough, he won, taking the 2001 GT Team Championship with G&W Motorsports.

This proved pivotal, and kick started a love affair with the "silly, 40 year old rear-engined car from Germany". He began collecting Porsches - starting with a 930 road car - and soon his relationship with the marque took on professional levels of worship. He founded the Heritage Motorwerks Porsche dealer in North Carolina, and built up a collection of cars widely regarded as the world's most significant private hoard of turbocharged Porsches.

Sadly, Matthew passed away in November 2010, but if you're already a fully subscribed Porsche enthusiast, you'll already know about his astonishing collection. And thus, you might be interested to know Gooding & Company has auctioned off his entire haul. The whole lot. Seventeen Porsches.

One of these includes a 1973 Porsche 917/30 Can-Am Spyder; a car packing a 1,000hp turbocharged flat-twelve engine, and one of four examples completed at the Porsche factory. It has been meticulously restored, was raced at the Monterey Historics, and was presented in Penske-Sunoco livery. It went for an astonishing £2.8m ($4.4m).

Click through for highlights from this fantabulous auction.

Images: Pawel Litwinski ©Gooding & Company

1973 Porsche 917/30 Can-Am Spyder, chassis 917-30-004
Sold: $4.4 million (£2.8m)

1984 Porsche 962, chassis 962-103
Sold: $1,925,000 (£1.2m)

1974 Porsche RSR Turbo Carrera 2.14, chassis 911 460 9016 (R9)
Sold: $3,245,000 (£2.07m)

1976 Porsche 935/76, chassis 930 570 0001 (R14)
Sold: $2,530,000 (£1.6m)

1985 Porsche 962, chassis 962-HR1
Sold: $935,000 (£596,000)

1997 Porsche 911 GT1 Evolution, chassis 993-GT1-004
Sold: $1,265,000 (£807,500)

1975 Porsche 934, Chassis 930 670 0155
Sold: $891,000 (£569,000)

1980 Porsche 924 Carrera GT Le Mans, chassis 924-003
Sold: $385,000 (£246,000)

1987 McLaren-Porsche MP4/3 Formula One, chassis MP4/3/1 
Sold: $858,000 (£548,000)

1981 Porsche 924 GTP "Le Mans", chassis 924-005
Sold: $308,000 (£197,000)

1995 Porsche 911 GT2 Evolution, chassis WP0ZZZ99ZTS393062
Sold: $357,500 (£228,000)

1992 Porsche 968 Turbo RS, chassis WPOZZZ96ZNS82006
Sold: $346,000 (£221,000)

1986 Porsche 944 Turbo Cup, chassis WP0ZZZ95ZGN154076
Sold: $79,200 (£50,600)

1988 Porsche 944 Turbo S, chassis WP0AA2957JN151272
Sold: $82,500 (£52,700)

1994 Porsche 968 Turbo S Clone, chassis WP0AA2961RS820772
Sold: $72,600 (£46,400)

1991 Porsche 944 S2 Cabriolet, chassis WP0CB2949MN440106
Sold: $39,600 (£25,328)