i use meguiars ultimate liquid wax around £25 online, and its so easy to use, and gives an amazing shine... ignore all these dealer applied paint sealants, as theyre a rip off, im an ex car valeter and they typically cost £15 and the charge you £299!!
also fabric protectors are a waste of money....... just clean the seats if you ever need to with an interior shampoo, or a wet&dry vac.... and as for people who spend 20 grand on a new car, then never clean it, i just dont get it?? my jazz is 6 years old next month, and looks like new :-)