yeah i would also say the rns is the best unit to go for but they are still like over 800quid on ebay..
i dont really use the satnav but its a good bonus.
the kenwood is nice hurdy but im not to keen on screens that flip, ive heard rumours about kenwoods sticking after awhile
Emeye jvc are a good make, ill look in to some of them.. id love an alpine but they two are expensive.
ill keep my eye on ebay, its worth buying a good system as i always have the music/radio on and being able to plav dvds and the use of satnav is very handy nowadays.