The general feature to consider and learn here is "Go to" versus "Go in" when used as an imperative. And the inflection is different because "Go to" is derogatory as is "Get in." As a result, they begin some orders. More frequently, I would say "Get in" with a younger relative if the reference were to get in (enter in order to abide/stay indefinitely in) a car rather than go to (abide/remain in) a room. And I say "Go to" much more often in superior status social situations than I do "Go in ..." Politely, I would encourage or welcome entrance away from me with "Go on in" (not "Get in"). "Go in" almost is never said in my dialect of American English in demanding reference in reference to a physical location; only objects (like a vehicle such as a truck, car, etc.). However, based on experience, I would expect some other international variant of English such as Australian, Singapore, or Indian sub-continent English to adapt and use "go in" as a command/order than my variant of English since prepositional associations with major general reference verbs (do, make, take, get, be, etc.) that turn them into particles are historically arbitrary more than they are actually locative in frames of reference.