Originally posted by SSJ_ReNe
yeah SSJ 4's wouldn't be able to be in DBZ even if they wanted to, because for 1 reason SSJ 4's only transform when Goku looks at the moon while in SSJ form turning into a Golden Oozaru, then turning into a SSJ 4 .
(not sure if Goku has a tail before hand or he looks into a magicall moon or something)
and for Vegeta he becomes a SSJ4 because Bulma makes the "Brute Ray" which turned him into a Golden Oozaru.
you made some small errors:
Goku's ssj3 form is insuficient to fight bebi vegeta, then, the old kai says that they need to pull out goku's tail, cuz then his dorment strenght wil awaken. so they jank out gokus tail, he gets send back to planet plant (bebi wished it back) and fights bebi, again in ssj3, but for some reason its stil not enough, then bebi beats the living crap outta goku, and goku lies half dead on the ground, then, he stares at the "full" earth (planet plant is right next to planet earth), then, his hart start pounding and ****, and he becomes a golden oozaru, he rampages threw planet plant, and then pan, his grand doughter, starts talking to him, then goku reverts from golden oozaru to ssj4
vegeta on the other hand gets turned, like you said, by bulmas 'Brute ray' (made by bulma to help bebi vegeta go golden oozaru). bulma shoots at vegeta with the ray, vegeta becomes oozaru, and pretends hes on a rampage, then he shrinks (golden oozaru is smaller then normal oozaru) and becomes golden, and then a big flash, and hes ssj4