Longer Search for R2-D2
The shooting script includes additional dialogue of Luke and C-3PO chasing after R2-D2 on the landspeeder. Luke fears they aren’t going to find Artoo and that his uncle isn’t going to take it well. C-3PO asks if it would help if Luke said it was C-3PO’s fault. Luke likes the idea and says he would probably only deactivate Threepio for a day or two, since Owen needs him. C-3PO gets upset at the idea of being deactivated and starts to blame Luke for taking off R2-D2’s restraining bolt. Luke interrupts C-3PO because he notices R2-D2 on the landspeeder’s scanner.
Why it was cut
This sequence was cut entirely for technical reasons. The crew shot Luke and C-3PO on the landspeeder with a decades-old cinema technique: rear projection, in which the characters sit on a vehicle with the background shown on a projector screen behind them to simulate movement. Films have been using this technique for driving scenes since the 1930s, but the effect did not look very convincing in Star Wars. As a result, all of the dialogue of this scene was cut without any detriment to the plot. Only Luke’s last line of dialogue about seeing R2-D2 was retained and used in a better looking wide shot of the landspeeder, instead of the closeup of this scene.
 “Star Wars: The Deleted Scenes #4: Threepio takes the wheel,” Episode Nothing: Star Wars in the 1970s, https://web.archive.org/web/20220105211401/https://episodenothing.blogspot.com/2015/05/star-wars-deleted-scenes-4-threepio.html; Rinzler, The Making of Star Wars, 211-212.