Only one prototype of the Phoenix was built. When it was learned what government regulations had to be met for safety and emission standards, Fitch, couldn't go any further. The prototype was actually the Fitch-Phoenix II. A standard Fitch-Phoenix had been planned, which would have had a stock Corvair motor. It would not have had front disc brakes and a few other features found on the Fitch-Phoenix II.
Based around the Corvair engine (which, with his Sprint conversions, John Fitch was supremely familiar), the rear-engined Phoenix had people giving Fitch real money in 1966 as deposits against delivery. But the planned run of 500 cars never happened. The Traffic Safety Act of 1966 was passed within weeks of the first showing of the Phoenix, and uncertainty about how it would be implemented kept Fitch from moving to production.