Super Saiyan 3 Vegeta

Some time a couple years after the destruction of Kid Buu Vegeta set out once more to surpass Goku. After a few months of excruciating training, going over 4000 times normal gravity,Vegeta finally achieved the Super Saiyan 3 form Vegeta upon reaching the Super Saiyan 3 form. In no time at all he and Goku were going at it like old times. At one point in the fight Vegeta almost killed Goku with his Full Power Final Flash technique. The turn out of the fight acctually led to Vegeta's victory. Vegeta was overwhelmed with pride, so much in fact he started to train Trunks to be a Super Saiyan 3, but that never happened, or did it?