He felt that a mid-engined road car would be too difficult for his buyers to handle, and it took many years for his engineers to convince him to adopt the layout.

This was advantageous for packaging reasons, as a compact engine/transmission meant the chassis could have a short overall wheelbase as well as a comfortable, spacious cabin.

It had a low, wedge shaped nose with hidden headlamps, a steeply raked windscreen and a wide rear section truncated by a vertical tail.

As a result of these aerodynamic studies, a spoiler was placed behind and above the passenger compartment, spanning the two buttresses or sail panels on either side of the engine cover.

This spoiler was intended to reduce drag, improve stability and direct air into the intakes on the top of the engine cover.

To this effect, the bodywork was split with a horizontal seam near the top of the wheel rims and everything below this point was painted satin black, including both front and rear bumpers.

The prototype's fuel filler was placed below the rear quarter window, but this was relocated to a buttress/sail panel in the production version.

[citation needed] Production 365 GT4 BB bodywork was constructed by Scaglietti and final assembly took place at Ferrari's factory in Maranello.

[10] Contemporary press reception to the 365 GT4 BB was positive and journalists praised the car's handling and straight line performance.

R&T testers reached a top speed of 175 mph, making the 365 GT4 BB the fastest road car tested at the time.

The larger displacement engine also allowed Ferrari to meet more stringent pollution and noise regulations without losing performance.

Although these figures are not as high as those published in other road tests, it was listed in the Guinness Book of Records as the world's fastest independently road-tested production car.

[13] Camshaft timing was changed and the Magneti Marelli "Dinoplex" electronic ignition system now had a built-in rev limiter.

Buyers could specify an optional interior trimmed with Ermenegildo Zegna wool cloth in the seats, door panels and headliner.

[13] Neither the BB, nor its closest competitor, Lamborghini Countach, were built from the factory to meet United States or Canadian safety and emissions regulations.

[15] Enzo Ferrari believed that emerging environmental and safety regulations and the 55 MPH national speed limit suggested the company's eight-cylinder cars would suffice in the Malaise era U.S.

This modification process, commonly known as "federalization", involved changes to the engine, instrumentation, lighting, seatbelts, and crash reinforcements.

The front bumper and subframe had to be extensively modified in order to meet the "5 mph" zero damage standard in effect at the time.

Carbureted models were modified with a secondary air injection system, catalytic converters, and various tuning adjustments in order to meet US emissions standards.

Also, the workshop manual does not consistently distinguish measurements between the carbureted (512) and injected (512i) engines except with respect to the fuel delivery system, even though it is common knowledge that differences exist.

18139 finished 6th overall at the 12 Hours of Sebring two months later, then was entered at Road Atlanta where broke another hub carrier during practice and Lime Rock, where it retired from the race due to a broken connecting rod.

The wheel arches were flared, a small rear spoiler and racing fuel filler were installed and the interior adapted with safety equipment including a roll bar, harness and fire extinguisher.

[9][25] After the failure of the first series, Ferrari worked on fixing the BB LM with a second development program in late 1978.

The production-based bodywork of the first BB LMs was replaced by a new design developed by Pininfarina which carried over very little of the original styling.

The pop-up headlights were now replaced by fixed units integrated into the fascia, while the tail was lengthened to the maximum allowed by regulations.

[9][26][27] The S2 design was further improved in 1980, including vertical side skirts to take advantage of ground effect, a larger air inlet duct in front of the rear wheels and a lighter chassis with fiberglass body panels, reducing weight by 100 kg (220 lb).

[9][28] The 512 BB LM was never raced by Scuderia Ferrari, but was instead campaigned by several independent teams with varying levels of factory support.

The BB LM was campaigned in World Endurance Championship and IMSA races as well as smaller local events from its introduction in 1978 through 1985.

[9] However, two accounts from Ferrari insiders suggest that "Berlinetta Boxer" is a backronym and the letters "BB" originally had a different meaning.

During development of the 365 GT4 BB, they began to refer to the car as "Brigitte Bardot", as they perceived the prototype to be exceptionally beautiful like the French actress.