If I remember well Paul, in your reply, 61 seconds before mine, you said something wrong like "Louis Brennan's gyrocar" (wich is another car) mixed with someting right (Gyro Transports System). You edited it and erased the Brennan part.
Well, I edited my post too and attributed the design to Tremulis (before I had just said he was involved I think).
I don't care who gets this point, but I want you to know that I didn't google your answer to find mine: I wouldn't have had time. I recognized the car and had a bookmarked page where I knew i could find the exact ID.