So upon rotating tires this weekend I realized how rusted my gas tank is.... entire thing is flaky rust, quite disturbing!!! so does anyone have a guide to installing a new one?

 

Are you sure? Its Plastic.

 

You're not talking about your mufflers are you?

 

I'm sure that's the OP is referring to they do look like gas tanks from the side lol

 

Just so you understand...on a gen1 mini (2002-2006/2008) the gas tank is UNDER thecrear seat....
Those rusty things you might be looking at in the rear are exhaust....the heat shield in the resinotor (on the s) usually goes first....

 

hahaha... okay I'm an idiot. it's the driver side muffler then
Must be the heat shield... so you guys think I should spring for new exhaust or let it go? lol

 

Have a shop take a look at it, the hangers may be done for, unless is really bad and you are seeing holes you can still use it, a new one is expensive, try a use one or an aftermarket or a JCW for that matter

 

You're supposed to inspect the exhaust system periodically and replace it when it starts leaking or becomes structurally unsound, but most folks just wait until the car suddenly gets really LOUD. I wouldn't let a overall rusty external appearance carry much weight as they can look externally rusty and still be sound. And you don't want a rusty muffler repair to drive you towards premature cat replacement as this gets into a lot of money.

- Mark