Every time I was ever at Andial which was many times they always had at least 1 959 and usually 2. They were the service center for North America.
Paul Allen which was Bill Gates partner owned the other one that was stuck in customs with Bill Gates 959. Even around that time there were others. I remember in Southern California and would see them at Monterey.
Here is some information I found online:
http://www.autoblog.com/2006/12/18/bill-gates-porsche-959-to-become-enemy-of-the-state/
The "Show or Display" exemption that was enacted under Bill Clinton's tenure as president has been a godsend for collectors and enthusiasts who love certain European and Asian vehicles that were never officially certified for U.S. road use, cars like the McLaren F1, Bugatti EB110, Jaguar XJ220, Maserati MC12, Mercedes-Benz CLK-DTM and GTR, and the Porsche 959. These are incredible cars that were never designed for American roads, and in turn needed some official "help" to get to these shores.
Some wealthy owners had taken it upon themselves to import these cars for their own collections even before the Show or Display legislation went into effect. Jerry Seinfeld was one of the first people to get a Porsche 959. He was joined by Microsoft partners Paul Allen and Bill Gates. Gates, in particular, was glad when the Show or Display went into effect so he didn't have to worry so much about blasting around Seattle in his Porsche supercar. Well, his days of no motoring worries may be over.
As part of an "environmental crackdown" in his home state of Washington, the Show or Display vehicles may lose their exemption. Governor Chris Gregoire is looking at ways to cut pollution and a prime target are catalytic converter-free cars like these exempted vehicles and their "gross emissions." Although Gates had recently joked that, "my Porsche days may be coming to a close," that was due to his wife Melinda's concerns more than any foreseen legislative problems. According to this Australian IT article, Bill's friends seem to think "he will not surrender his right to drive the 959 without a fight." Having seen a few of these in action over the years, we hope that cooler heads prevail and they work out a compromise.