In today’s car selling climate, automakers have been tasked with building cars that are engaging, efficient, and most of all, affordable. Fuel economy standards, emissions regulations, and miserly car buyers have forced companies to downsize engines and develop electric and hybrid technology to supplement the internal combustion engine. In today’s eco-friendly world, a car like the 16-cylinder Mosler Twinstar would be shunned.

But back in the year 2000, the new millennium seemed so bright and full of potential, the perfect climate for a car as weird and wild as the dual-engined luxury barge. Based on a standard front-drive 1999 Cadillac Eldorado with a Northstar V8 under the hood, Mosler engineers shoehorned a second, 300 horsepower Northstar into the trunk to power the rear wheels. The resulting four-wheel drive, 575 Mosler Twinstar was unlike anything else on the road at the time.

But where did the inspiration come from, and how did they do it? Those are some of the questions we asked Jo Borras, a former Mosler engineer who actually worked on the Twinstar.

According to Borras, the Mosler team was engaged in building a follow-up to the mid-engine Consulier, to be called the “HP 40” or High Performance, 40 MPG. “The idea was to put a drivetrain/subframe into the back of the Eldo to prove out how something with a mid engine and that long wheelbase would drive and handle,” says Borras.  “Warren (Mosler) had some golf buddies in the shop while the Eldo was in process, and the guy saw it and said ‘Wow, cool- a twin engine car.’ (or something) and Warren kind of decided to have his engineers make it happen.”

Thus, from an off-hand comment was the Mosler Twinstar born. And according to Borras, the build wasn’t as difficult as some might think. “The subframe GM used was, dimensionally, the ‘right’ size to fit in the trunk,” says Borras. “The track was a bit narrower, so we had to make some fender flares.  The biggest issue there was getting the ducts that fed the rear radiators to both look passable and be functional.”

Amazingly, the first Twinstar took just a couple of months to build, and according to Borras it handled “surprisingly well” despite the added heft of a second engine. It even made it into an issue of Car & Driver, where the buff book laid down a 0 to 60 MPH time of just 5 seconds. Production began soon after, though ultimately just five cars would be built, and three for a single customer.

“I was on the phone, and I was telling the customer all about how it handled and how it was integrated and how nice it was to drive compared to something like a Viper or blah blah, and he cut me off,” says Borras.

“He said ‘Look, that’s great.  If someone walks up to the front of my car and shoots out the radiator, can I still drive away on the rear engine?’”

“I kind of blinked, and Warren Mosler happened to be there next to me (I remember we were on the Consulier/TEC side of the building and the call was forwarded to me), and I asked him.  He said, ‘I don’t see why not.’ So I told the guy, ‘I don’t see why not.’”

He said:  ‘I’ll take three.’”

Today, the only cars with sixteen cylinders on tap cost hundreds of thousands of dollars, but the eBay auction for this Mosler Twinstar was asking just $40,000. Alas, a high bid of $17,103 failed to meet the auction reserve, meaning this sixteen cylinder Cadillac monster will stay in hibernation, at least for now.