Star Wars Episode 4: A New Hope - R4-D5 Can Bilocate
I that scene where Luke and Uncle Owen buy the astromech droid R4-D5 from the Jawas, look closely at the scene after the droid explodes (this droid's got a bad motivator!). You'll see the EXACT SAME droid bleeping and blooping around in its previous spot, as if nothing happened.
first of all, its R5-D4 not R4-D5, and also some droids look alike, take the very first scene with 3PO and R2, there is another droid that looks almost EXACTLY like 3PO
Sorry, but it is a mistake. If you watch the scene, there are no other R4-D5's. And besides, you can see Jawas prepping R4-D4, and it's the same shot from earlier before he bit the dust.
The real slipup is when Luke says, "this R2 has a bad motivator" when he was referring to the R5 unit. Also, how does the R5-D4 droid makes its way on one of the X-wings at the battle of Yavin. As far as I know, each astromech droid has a unique ID. You may have many R2 units but only one R2-D2.
dmaul - this has been addressed in Star Wars Insider. "R2 unit" has come to be used as a synonym for "astromech droid" in the Star Wars universe, just as "Q-tip" is used to mean any small cotton swab, or "Xerox" is used synonymously with "photocopier."