My boys lucked out and rode a total of three of the gold "cars"...but that was totally luck.
While we were waiting in line for Dumbo (I swear it was 90 minutes at least!) the same thing happened over and over. The people entering at the handicapped entrance were allowed to enter first, and they would take the golden Dumbo. (Without sounding rude, I personally know people who have stretched the truth to be able to use this entrance system...and a lot of these folks sure could run once that gate was opened.) It was completely dumb luck that the lady who came in thru that way when we finally got to the front really was obviously handicapped...and she took the Dumbo closest to that gate, allowing my son to run around and snag the gold Dumbo.
I guess, depending on how many people are in your party and how long you might have to wait, it could get to a point where you'd be glad to settle for a photo on the picture op Dumbo.
The teacups were much easier. The lines there weren't nearly as long and my older son was easily able to get on the golden teacup.
We ended up on the golden boat in Storybook Land (I STILL don't get the point of THAT ride, lol!) by chance.
I'm glad my kids didn't have their hearts set on riding all the golden cars...with the way the lines were, we could have spent all 3 1/2 of our Disney days just trying to succeed!