Range Rover sound systems are supposedly designed to withstand the rigors of off-road use but I personally have found they need replacing or repairing at regular intervals. One annoying feature is the need to enter the 4-digit radio code every time the battery is reconnected after some repair operation. Some people have reported frustration in attempting to get the radio working again; for example John Rowntree had problems after the battery was out for an extensive service visit; one of the buttons did not seem to work. After a certain number of wrong attempts, the system freezes and you have to leave it on for an hour before trying again. John found that indeed, leaving it on for 90 minutes was the key. It took the code fine at that point.