Hey Rock.
I think the car you're referring to was the rotary powered one campaigned by Harvard Daniels.
Google doesn't turn much up on it unfortunately. If you do a image search for "Harvard Daniels Eureka" there's still one pic of it that comes up in the Google cache from the Hibiscus Motorsport Club site but the image itself appears to have been removed.
He gets a mention in a few forums too. In particular for rolling the Eureka in a rally sprint event.
There's footage of it in action including the rollover on YouTube at
http://www.youtube.com/watch?v=W4wdQGqxVEk (at about 7:15)