hey all, just bought a 99' clio and im looking to change the default renault cd player for a new one of my own. If i change the cd player will the steering wheel volume controls and the display screen with the clock and radio station names etc all stop working???

yes unfortunetly they will. In all honesty talking from experience the standard cd player isn't bad, aftermarket one's without spending silly money don't make much difference. you could argue looks but even at that most stick out far further forward than the standard one.
you can buy a connector for most aftermarket cd players to connect the steering wheel controls,your best looking into this before you purchase the cd player though as some makers charge up to 70-80 pounds