Hi, not sure if this is the right place but here goes. I have a mk 4 astra (02 reg) which had a jvc head unit in when i purchased it. I've bought a newer unit on ebay but the lead at the back doesn't fit. I have a 16 pin socket in the car but the head unit has what appears to be 2 adjacent sockets, one above the other. What do i need to fit the new one? sorry for the laymans terms, i know absolutely nothing about cars.