What a handsome fella!!
And he's definitely a big guy, going by his size in relation to the car! And, Yep, there are red dun roans.
Since halter judges the horse against the standard of conformational and movement perfection for the breed, it's hard to say how successful he'll be at a given level without confo shots. Going by the pic posted, he looks to be fairly well balanced, slightly long through the back (could be an optical illusion because his neck isn't stretched out in the pic), but with a good solid hind end and nicely formed legs. Perhaps slightly tied in at the knees, but it's difficult to see for sure in the pic - if he is, that'll count against him in the ring. Again, real confo shots and/or video of his movement would be really helpful if/when you can get them.
I don't see anything in this pic that would prevent him from showing in about anything that you want to do!