Iron and oxygen
you only replace them if they are damaged or rusted out
No it is not illegal. It is recommended that you inspect a car before you buy.
First remove the paint around the rusted area, grind down the rusted spot, then paint over the spot and cover the rest of your car you don't wish to paint with something like newspaper.
there rusted...there bent....there old...you need to replace them
anything kind of crap you keep putting money in can be a good car enless its rusted out but people still rebuild
It depend on which state you are doing it in and also how much rust you have
Broken or collapsed springs? rusted or rotted shock towers?
yes if the structural integrity is compromised like the frame being rusted out as an example
small hole in the tank or in lines ..even rusted lines
No, this is uncommon. It depends on where you live or where you've driven the car.
Because its rusted on the hub and you have to hit it very hard w/ a hammer. Unless on some cars its bolted to the spindle. What car is this for?
Yes. Especially if it is rusted because your tire will fall off.