I use liberal amounts of white spirit inside and out and it really gets rid of all the grime, it shows up all my stone chips too. Wipe on, let it dry in then polish it off, gives a mirror shine. Then i use tesco eco screen wash, the clear screen wash with no additives. It does not smear like halfords stuff or the nasty blue screenwash stuff you can get. I wipe the wiper blades with a bit of white aspirit too, it gets loads of muck off of them.