
Firstly lets start with the head unit, There are two types available, 1> Double Din and 2> Single Din the standard stereo is not a standard size, so firstly you will need a fascia adapter, dependent on which Stereo you have, both fascias simple plug in where your old stereo was removed from

Stereo Removal Keys if you dont have them are here for £1.95 :
http://www.carstereos4u.co.uk/renault-stereo-removal-keys/renault-stereo-removal-keys-pc5-83-2086022-392102-.php
1> Double Din Adapter (This can also be used for a single din) is here for £9.99
http://www.incarmusic.co.uk/product/2479-381/FP0803-CD-Radio-Facia-Panel-Fascia-Adaptor-for-Renault-Megane
2> Single Din Adapter is here for £ 3.99
http://www.incarmusic.co.uk/product/2477-381/FP0801-Car-Stereo-Facia-Panel-Fascia-Adaptor-for-Renault
If Changing from standard stereo you will need this adapter for your Radio Aerial its £2.95:
http://www.incarmusic.co.uk/product/1591-250/PC527-Car-Aerial-Antenna-Connector-for-Renault
if you wish to keep your steering wheel controls, check out this adapter, from £20 depending on the year of your Megane:
http://www.incarmusic.co.uk/product/2739-417/CTSRN003-Steering-Wheel-Interface-Stalk-Control-Adaptor-for-Renault
Sometimes people dont wish to Change their Headunit, and preffer the standard unit. In this case you may be after something else to add functionality to your existing standard Stereo. So I have found a couple of items which may be of interest, (I havent shopped around for these two items, so I cant guarantee these are the best prices available, so do look them up on a price comparisson site first)
1> Ipod Connector / charger for standard Renault headunit £47.99
http://www.caraudioni.com/ipod-iphone-oem-head-units-renault-ipod-iphone-adaptor-c-145_684_781_796/connects-2-ctarnipod003-ipod-adapter-for-renault-clio-kangoo-p-4151
2> Standard Aux Connector for standard Renault headunit £26.95
http://www.dynamicsounds.co.uk/connects-ctvrnx001-renault-clio-kangoo-megane-scenic-interface-adaptor-p-8743.html
Later on this evening I will add a list of compatable speakers, after I have done a bit of research
