Toriyama had nothing to do with SSJ4 or GT, I doubt he'd care.
Just as he came up with the "Z" title, Toriyama came up with the name "GT" as well. In his Dragon Box GT intro, he says that "in car lingo, GT means 'Gran Turismo': a fast, high-powered car, in other words. But in this case, I had GT mean 'Grand Touring', a great journey, since the scenario was that they'd be running around the universe." The GT Perfect File Vol. 1 mentions that the name could also mean "Galaxy Touring", though this doesn't seem to have been Toriyama's intention.
Besides coming up with the title, Toriyama also drew a rough design for the GT logo, which is shown on page 82 of the GT Perfect File Vol. 2 and was reprinted in the Dragon Book included with the Dragon Box GT. His design was essentially the same as what the logo ultimately ended up looking like.
Original Draft
Anime Appearance
Toriyama designed the "several years later" appearance of the main DragonBall GT cast, including the infamous moustache-blighted Vegeta, which were featured in the GT Perfect File Vol. 1 on page 89:
GT Main Character Designs
In addition to these black and white designs, Toriyama also made several color pictures of Goku, Pan, and Trunks. The first is simply a colored version of the above pictures of them. There's also a stand-alone picture of Goku using alternate colors than what he ended up having in DragonBall GT: orange shirt and blue pants, instead of blue shirt and orange pants.
Colored Draft #1
Colored Draft #2
Toriyama's design for Giru was originally printed in Weekly Jump No. 52, 1995. It's been reprinted in Daizenshuu 7 and the GT Perfect Files, though the Perfect Files reprint lacks Toriyama's notes. Apparently Giru was not named at this point, and was simply labeled as the "Meddling Robot".
Giru Design
Toriyama designed the spaceship which Goku and co. use to hunt for the dragonballs throughout the universe. Like his Giru design, Toriyama's spaceship drawings were printed in Weekly Jump No. 52, 1995, and later reprinted in Daizenshuu 7 and the GT Perfect File Vol. 1. They include fairly detailed notes, which unfortunately are left out of the Perfect Files reprint.
Spaceship Design
Toriyama drew three (that we know about) color pictures of Goku, Pan, and Trunks adventuring on various alien planets. The first two were, as you might guess by now, printed in Weekly Jump No. 52, 1995, and were later included in Daizenshuu 7 and the GT Perfect Files. The first shows the gang on Planet Mommath, hiding behind a giant glass bottle as giants curiously check out their ship. Planet Mommath and the giants appear in
DragonBall GT episode 6. The next picture shows them on the desert planet Kahra (possibly a pun on
kara, meaning "empty"). This picture strongly resembles Planet Ruhdeze, seen in DragonBall GT episode 16. Finally, Toriyama made a third GT picture for a calendar included in Weekly Jump No. 3/4, 1996. It shows Goku and co. beating up a bunch of aliens on a mysterious planet, none of which were used in DragonBall GT.
Planet Sketch #1
Planet Sketch #2
Planet Sketch #3
http://i1155.photobucket.com/albums/p543/Se7en25/1249339-toriyama_ssj4_dragonbox_super.jpg
Edited by PRP777, 26 November 2012 - 07:58 PM.