Once you get your paintwork to the shine you want to keep it would recomend getting something called Diamond seal or Supaguard they work a bit like the stuff you get to stop your carpet from wearing out or staining, but it goes on the bodywork of your car, i was a valeter for 8 years and we used to do supaguard on new vehicles, so as long as you look after it properly once the treatment is done it should oulast the engine easily. I haved seen first hand that this kind of thing does work (oh and im not a salesman for it either) check out some local garages a lot of them do it nowadays. costs around �200