I am also installing into a 2004 Megane II sport saloon. I have at this stage chosen to place my Lilliput 7” Touch screen on a home made slide beneath the standard radio. If you remove the tray unit under the radio (assuming you don’t have the factory fit 6 CD changer) you will find another standard din opening. I have filed away the bottom two sides to allow the Lilliput to fit within. If I was to do it all again I would get a motorized VGA monitor and put up with the expensive.
The Megane's a very light car and you will have problems with reflections on any screen you put in.
The audio I have eventually had to purchase the Connects2 VRNX001 @ £55.00 after trying FM modulators etc. The sound's very good and it allows the volume +/- , mute from the steering controls. This unit fits all Renault radios with the word ‘Tuner List’ on the front. Lift out your radio and you should see a blue connector where the cd changer connects.
Ill post some pic’s once I get time.
Compaq EN SFF, P3 450Mhz pc
Windows XP pro
GPS - Globalsat BU303 GPS Mouse − USB
GPS software – MapMonkey
Software front end – MediaCruiser - modified