i have a creative zen extra 60 gb mp3 player i want a head unit that i can attach it to
ps i have around £300 to spend thanks

 

Farmer I am in a similar situation, and have done a fair bit of research, seems to be all you need is a headunit that has an AUX input option (often used for CD changers).
With this you then hook up an additional cable (some HU come with it if not £10-£30 depends on brand) that has two phono connectors at the end, plug these into an adaptor to go into your headphone socket (£2 from Maplins) and off you go.

Not actually bought mine yet but almost there.

As yet I have not found a headunnit that will control the MP3 player so you still have to select the tracks via that.

Link below is for a site which has models that will do the job to give you an idea.

http://www.caraudiodirect.co.uk/help/ipodfriendly.html

Hope this helps.

Steve