Not sure if anyone has already posted this but i have a clio mk3 197 sport and had to disconnect the battery which meant radio needed code.
Took me hours to find out but finally cracked it and thought i would help others out.....
When the four 0000 are displayed and the first 0 is flashing, using the wheel on the steering wheel control .....
1. turn wheel and 0 will change, keep doing this until the number you require is displayed.
2. pull the wheel towards you and it will select the second 0,
3. again use the wheel to select your number and repeat this for all four 0.
4. At the end whilst the fourth number is flashing, pull wheel towards you and hold it for a few seconds and the radio comes on!!!!!!!!!!!!
Just re-tune all your channels and your away.
Hope this helps