Hi Jennifer:
Welcome back to the Disney Parks Moms Panel. This is actually a great question. I am very sensitive to smells, so I totally understand your concern.
Lights, Motors, Action! Extreme Stunt Show is an exciting experience at Disney's Hollywood Studios, but I have found that there is a definite odour during the performance. For me the smell is much more severe on hot days, as opposed to cooler days, but regardless, I have always noticed a smell. The only time I will watch the show is when the weather is cooler, and I make sure I am seated close to an exit, so as soon as the show is over I can make a quick escape.
Overall, the experience is a fantastic, so deciding to skip it could be tough. I would suggest walking by the experience, as the show is in progress. This will give you a good idea as to the strength of the odours and if you could handle the smell for the entire performance.
I hope that helps Jennifer. Have a magical day!
Stephanie