Ok - this is a big warning - Caution mistakes like this could kill you.
A) Auto Seats made in the last ten years are all tested for
construction and crash worthyness. enough said. Rust is not a problem.
get powdercoated if necessary. and use marine grade grease. Do not weld
on seats use grade 8 bolts and design to bolt on. I design products for
a living - use good factory made components in this part of you vech.
18Gs of force is not uncommon x 150lbs(driver) = lethal force