Freight-loading external rover
- "To use the F-LER, I'd have to get out of my YT-1300. Who wants that?"
- ―A YT-1300 pilot
The freight-loading external rover, also known as the F-LER, was a small, extremely rare single-pilot starship that was manufactured by the Corellian Engineering Corporation for use in conjunction with the YT-1300 light freighter.
History
The vehicle was developed by the Corellian Engineering Corporation (CEC) designer Tem Riffle, who was inspired by a tug that he had observed towing a YT-1200 freighter. The F-LER was designed to fit between the forward mandibles of a YT-1300, and Riffle envisaged that the rover could be a cargo handler, to deliver freight to locations that the YT-1300 was too large to reach. CEC's executives favored Riffle's idea, and many other designers concluded that the addition of a F-LER to a YT-1300 gave the freighter a sleeker look, while CEC's marketing department believed that YT-1300 owners would want to fill in the gap between the forward mandibles. A prototype F-LER was developed and successfully tested, and CEC began a limited production run of the design. CEC's marketing department also carried out a survey of 500 commercial YT-1300 pilots, to assess the F-LER's market potential.
However, just over a week into the F-LER's production run, the survey results were collated and revealed that most of the surveyed pilots were not interested in the F-LER, because they thought that it would get in the way when loading cargo. As a result, CEC ceased production of the vessel and the F-LER was never sold commercially. One hundred were saved to be used as tugs at CEC orbital assembly facilities, while the rest were scrapped. Eventually, a small number of F-LERs made it onto the open market and a few were modified and fitted with Ap/11 double laser cannons. The F-LER's rarity was such that by 4 ABY, a refurbished F-LER was worth more than a vintage "stock" YT-1300.
Despite the F-LER's commercial failure, the research and development that went into the F-LER later resulted in the production of the YT-XC "mini-fighter," a small exploration ship that was designed to be carried aboard the YT-1300.
Behind the scenes

The F-LER was originally a toy planned for the Kenner toys storyline The Epic Continues, as a supplement for the Kenner Millennium Falcon toy. However, because of that line's cancellation, the toy was never released. Pre-production photos were implemented into a special binder containing toys from the toyline, which were eventually shown to the public with the article Tales of Phantom Toys in Issue 2 of Star Wars Galaxy Magazine.
The craft was eventually named and made an official part of Star Wars Legends with the release of the Millennium Falcon Owner's Workshop Manual.
Sources

The Epic Continues (Cancelled)
"Galactic Bazaar: Tales of Phantom Toys" – Star Wars Galaxy Magazine 2 (First appearance)
- Millennium Falcon Owner's Workshop Manual (First identified as Freight-loading external rover)
Offscreen, but Not Forgotten: Mini-Rigs, Body-Rigs, and Other Kenner Vehicles on StarWars.com (backup link not verified!)
"Classic Moment: The Fastest Hunk of Junk in the Toybox!" – Star Wars Insider 157