I have a renault laguna every time i switch the engine off it loses the rad?

Sounds like the radio is not the original one. Take it out, and switch the yellow and red wires. They will be as part of a set of three including the black earth wire
I can't remember which was round they should go, but if the radio works but doesn't keep it's memory it sounds like the permanent supply is wrong. Try switching the yellow and red wires - it should sort it.

Toby Aiken
July 2008