I'm sure this has already been answered somewhere, but I was unable to find it.

Is it possible to change the setups the AI uses in single-player mode? What I really want to do is play with added weights, intake restrictions, etc, not change any of the tire pressures, suspension, and so forth. (maybe that makes a difference? :shrug

I'm looking for any option that would allow me to do this. (add-ons, how to open/change .set files, anything really)

You can make them use your setup.
Options > Misc > AI use player setup: [yes].
e:Afaik, if you`re changing this option with AI cars on grid, you`ll have to remove and add them again, to have effect.

Does this work if I'm driving a different car? or not driving at all?

Yes, you have to pick some car, a setup, add AI.
Pick another car, pick a setup for it, add another AI which will have these "settings" applied, different from first.

You can add how many cars you like, with a different setup from eachother.
It will persist after a LFS restart, as long as you don`t remove them from grid.

This stands for skins too.

alright thanks