In 1954, Greyhound introduced the 40-foot-long, two-level General Motors PD 4501 Scenicruiser.
This sent its main rival, Continental Trailways, on a hunt for a unique design of its own.
It first contacted Flxible of Loudonville, Ohio.
Flxible agreed to produce Continental's dream coach on condition that Continental paid all design and tooling costs up front.
As Continental had bought the Santa Fe Trail Transportation Company (the large bus operations of the Santa Fe Railway) in 1948 and transcontinental carrier American Buslines in 1953, they were not flush with cash at the time and started looking elsewhere.
Mack, Beck and Fitzjohn either couldn't or wouldn't build this new bus (Beck and Fitzjohn were out of business by 1958 and Mack left the bus and coach business in 1960) unless the upfront costs were paid in advance.

That sent Maurice E. Moore, Continental's CEO, to Europe looking for a supplier.
Eventually he made an agreement with the German manufacturer Kässbohrer for the production of a prototype, which was completed in 1956 and shipped to Houston.
In the meantime Moore ordered 113 Vista-Liner 100 coaches from Flxible for delivery in 1955 and 1956.
The Vista-Liner (commonly called the VL100) was an advanced two level design but it was only 35 feet long with eight fewer seats than the Scenicruiser.
The difference in height between decks was about of half that of the Scenicruiser so it had much less space underneath for baggage and package express shipments.
The VL100 had some design input from Continental.
It was also noticeably underpowered (it had a 175 HP Cummins JT-600 diesel engine) which caused certain timetables to be adjusted on longer journeys.
On the other hand, the VL100 had BF Goodrich Torsilastic suspension (independent on the front wheels) for an excellent ride and a very fresh exterior design.
The suspension and certain visual design aspects of the VL100 were integrated into the design of the future Eagle coaches that Kässbohrer built as Setras.

The first 55 Golden Eagles were built by Kässbohrer.
The first Golden Eagle was a prototype that differed in a number of ways from the production versions.
After about a year in service Continental placed an order for 50 more modified versions based on lessons learned from the prototype.
The largest external difference was a new design for the six-piece windshield because drivers complained that the original design had them baking in the Texas sun even with air conditioning.
They were part of an order for 185 highway coaches manufactured under a contract with Continental Trailways.
Of this original group, four were articulated Super Golden Eagles.
 All of these coaches were of the 'Setra Design' which meant that they were 'integral' coaches without a separate body and chassis.
Kässbohrer took the German words selbst tragend (self-carrying) for a trademark in the form of Setra, a name formed from the first letters of those two words.

Golden Eagles originally contained an aircraft-style galley plus a rear lounge that had two tables with pairs of facing seats, observation windows and other luxury features such as piped in music, newspapers and magazines.
An on-board hostess served snacks and drinks en route and other amenities such as pillows and blankets were available.
The exterior aluminum siding was anodized in gold, hence the Golden Eagle name.
The standard version without the galley and lounge was called the Silver Eagle because the aluminum siding was in silver.
41 Silver Eagles followed their Golden Eagle sisters down Kässbohrer's production line in 1958 and became the standard fleet bus for Continental Trailways.
The first Eagle buses were powered by MAN D1566 diesel engines and ZF Media preselector six speed transmissions from Germany.
The four Super Golden Eagles had more powerful Rolls Royce diesel engines.
No Eagles were produced in 1959 while Continental gained experience with its new fleet.
Continental suggested a number of design changes to Kässbohrer that included a new front end and a standard American powertrain.
The result was the NEW Silver
In 1954, Greyhound introduced the 40-foot-long, two-level General Motors PD 4501 Scenicruiser. This sent its main rival, Continental Trailways, on a hunt for a unique design of its own. It first contacted Flxible of Loudonville, Ohio. Flxible agreed to produce Continental's dream coach on condition that Continental paid all design and tooling costs up front. As Continental had bought the Santa Fe Trail Transportation Company (the large bus operations of the Santa Fe Railway) in 1948 and transcontinental carrier American Buslines in 1953, they were not flush with cash at the time and started looking elsewhere. Mack, Beck and Fitzjohn either couldn't or wouldn't build this new bus (Beck and Fitzjohn were out of business by 1958 and Mack left the bus and coach business in 1960) unless the upfront costs were paid in advance.
That sent Maurice E. Moore, Continental's CEO, to Europe looking for a supplier. Eventually he made an agreement with the German manufacturer Kässbohrer for the production of a prototype, which was completed in 1956 and shipped to Houston. In the meantime Moore ordered 113 Vista-Liner 100 coaches from Flxible for delivery in 1955 and 1956. The Vista-Liner (commonly called the VL100) was an advanced two level design but it was only 35 feet long with eight fewer seats than the Scenicruiser. The difference in height between decks was about of half that of the Scenicruiser so it had much less space underneath for baggage and package express shipments. The VL100 had some design input from Continental. It was also noticeably underpowered (it had a 175 HP Cummins JT-600 diesel engine) which caused certain timetables to be adjusted on longer journeys. On the other hand, the VL100 had BF Goodrich Torsilastic suspension (independent on the front wheels) for an excellent ride and a very fresh exterior design. The suspension and certain visual design aspects of the VL100 were integrated into the design of the future Eagle coaches that Kässbohrer built as Setras.
The first 55 Golden Eagles were built by Kässbohrer. The first Golden Eagle was a prototype that differed in a number of ways from the production versions. After about a year in service Continental placed an order for 50 more modified versions based on lessons learned from the prototype. The largest external difference was a new design for the six-piece windshield because drivers complained that the original design had them baking in the Texas sun even with air conditioning. They were part of an order for 185 highway coaches manufactured under a contract with Continental Trailways. Of this original group, four were articulated Super Golden Eagles.  All of these coaches were of the 'Setra Design' which meant that they were 'integral' coaches without a separate body and chassis. Kässbohrer took the German words selbst tragend (self-carrying) for a trademark in the form of Setra, a name formed from the first letters of those two words.
Golden Eagles originally contained an aircraft-style galley plus a rear lounge that had two tables with pairs of facing seats, observation windows and other luxury features such as piped in music, newspapers and magazines. An on-board hostess served snacks and drinks en route and other amenities such as pillows and blankets were available. The exterior aluminum siding was anodized in gold, hence the Golden Eagle name. The standard version without the galley and lounge was called the Silver Eagle because the aluminum siding was in silver. 41 Silver Eagles followed their Golden Eagle sisters down Kässbohrer's production line in 1958 and became the standard fleet bus for Continental Trailways. The first Eagle buses were powered by MAN D1566 diesel engines and ZF Media preselector six speed transmissions from Germany. The four Super Golden Eagles had more powerful Rolls Royce diesel engines. No Eagles were produced in 1959 while Continental gained experience with its new fleet. Continental suggested a number of design changes to Kässbohrer that included a new front end and a standard American powertrain. The result was the NEW Silver
Eagle Bus