Basically that's the idea, but with enhancements. You want to make a game of it. Start with the engine off and teach her to jump in, jump out, get a treat. This should be a fun, upbeat play-time feeling. Once she "gets" it, have her jump in, get a treat, jump out, lather, rinse, repeat.
Then extend the time she waits for a treat.
Now because she's comfortable with the rig off, this part will seem silly and too easy, but do it anyway because it will help you change the association and teach her the game for the next step.
So next, you'll fire it up and let it idle and then start from the beginning. In, out, treat. In, out, treat. In, treat, out. FUN. You aren't in a hurry here because each repetition is putting another layer of new conditioning over the old one.
Slowly extend the time in the rig running. Your goal is NEVER to have her get to where she's showing signs of nerves or discomfort. You are re-conditioning her to feel comfortable in the rig.
Once she gets comfortable, you can let her eat in there, hang out a little, whatever.
Then you move it, but only a few feet the first time. In, move back twenty feet, forward twenty, stop, treat, out. Remember it's fun! This is a game. Then short short trips.... down the street to the park a block away, do something FUN.
The big challenge will be to keep from trying to push too fast. Slow is fast here. You'll get faster results by going slower because you're not trying to get a specific behavior, rather you are creating a new association. So short repetitions will do more to reinforce it, while going too far can push her back and reinforce the old bad associations.
Keep us posted.
