I bought some new rims for my car, and after it rained, my rotors rusted right up. Its surface rust (if you know what I mean), and the cars still stops fine, and after driving for a few minutes, the old rotor finish shines thru. It only goes back to the rust color after I let the car sit. Should i be concerned?

 

no. steel rusts. get some zinc plated rotors if you don't want to deal with the rust issue.

 

this is the wheels and tires forum....rotors would better be discussed in the generation or general forums....

but to answer your question quicky.....no, that is perfectly normal for rotors. Even zinc-plated rotors will get surface rust after the zinc-plating wears off after a while.