Fairly sure these are by Jin Kim? They have very similar styles, I think Glen Keane is a bit more flowy though.
Flynn Rider Concept Art by Glen Keane
Do not browse the Glen Keane tumblr tag unless you want to be rendered speechless by the sheer POWER AND MIGHT of his sketches.
GLEN KEANE /foams at mouth
A lot of these drawings were actually done by Jin Kim! (the facial expressions chart, and a few of the standing poses) All gorgeous work, all masterfully executed. The guys are geniuses.
Hair troubles! (video)
This makes me uncomfortable
Im laughing too hard
I am laughing WAYYYYY too hard at this
If you wanna see how far computer animation has come, just look at that hair. Hair is so hard to animate.