[LMH]

Not that I've noticed and that's on a 50 y/o car. (I've been working on an original) The body is pretty well attached and doesn't show any sign of loosening as far as I have seen. It's never been off the chassis.
Going to depend a lot on how the car has been used though.
This is in terms of an original car. David Kirkham could probably tell you if it's been an issue with his cars but I'd be surprised if they have a problem. Less frame flex than an original car.
Larry