what do I need to plug my MP3 player into our Nissan car radio??

[quartzlog]

I have a sony mp3 stick with a 'normal' USB end to it to stick it into my laptop to charge it.  I want to plug it into my nissan radio (Xtrons) in our motorhome , SO I bought a USB adaptor to reduce it to a micro usb but it still doesn't fit.  How do I found out what sort of adaptor I need?  

[soppysofty]

The USB slot appears to be on the bottom left hand corner of the unit as you look at it.

If it does not take a standard USB female plug then I can only suggest that you contact the manufacturer through their web site and ask the question.