Rust spots under the spare wheel (underneath the car)

[a3ternus]

Is there anything I can do about it ?!?
Could I possibly stop the rust from expanding ?!?
There are 2 small circular spots 4cm in diameter ie not much,but you notice them...
A3TeRnuS

[nando]

you could grind them out and primer them to keep the rust from spreading. If you have rust there you probably have other problems too, like a leaky trunk seal, antenna grommet or maybe tailight gaskets..

[rs4pro3]

one of my 318i's had this problem also but the whole floor under the spair tire was rusty. I used a wire wheel in my drill and ground away the rust then Brushed Rust convertor on which turns the rust to primer. I put like three coats of that on then sprayed over it with some color that was close to the factory color but not a perfect match.