what are people using as plugs in stripped out race car chassis?

[thehounder]

In my race car, I have a bunch of holes in the back seat area that were left over during the conversion from a street car to a race car. What are folks doing to fix these?

[eacmen]

I had some bolt-sized holes, used some of those plastic push-rivets with some RTV.

[Gt4]

On my last E46 M3 race car build, I welded sheet metal on all of them. Reuse the round left pieces over from hole saw A-B pillars gussets

[thehounder]

Thank you both