They are anodized m8... they are VERY rusty cars though when you look under the bonnet! The anodized part isnt as good as it sounds either as for whatever reason the paint on these cars doesnt like to stick to it and tends to flake off in big chunks, especially around the arches
Galvanised thats the word, dunno where anodised came from. Every time i have used kurust, i've ground back to shiny metal got rid of every tiny bit of rust, drowned the metal in it, zinc primer, primer, paint and laquer, its taken literally weeks to come back through. doesnt even work on tiny stone chips. a few people i know have used it and it really doesnt have an effect.
tbh i dont really see many 306's, i've seen real sheddy ones with bits falling off but they've never been rusty.