Order of assembly? From a bare shell

Epoxy primer DTM will stick to even cat chit. Worth the $, and you do not have to buy the highest price stuff out there for it to work. Then covering with Rustoleum is a cheap and good avenue. You can buy a spray gun cheap, that shoots a qt. or gallon of undercoat like the factory used. Some undercoats can be painted also.
Like said, I hope to have a lift by the time I hot 90!!
Don't it make you feel good to see the bottom of your car so clean and pretty!! Ya better hurry up, winter is just a week away up there!!??????
My car doesn't seem to have any undercoating, making all this easier LOL. Just cleaning some surface rust (now theat the driver floorboard has been replaced) lots of midwest dirt.