Good job on the polish, but if you have done no more than that, the paintwork is not protected at all - you have done the shining bit only! Rain and chemicals can now attack the finish.
To protect the paint, you will need a protective layer(s). You can either use a wax or sealant for this. Without this protective layer(s), rain and salt will just sit on your paintwork in sheets. I prefer a sealant layer for extra shine, then a Carnauba wax over that to make the paintwork richer looking.
See
http://www.polishedbliss.co.uk/acata...s_protect.htmlfor an excellent guide on how to protect that lovely polished finish you have achieved.