vectra c 1.9cdti 2006

1. Are all the auto dim mirrors the same on 02>09 vectra c, i want to fit one but the cheapest ive seen is for an 05 if they are the same i guess the electrical sockets are different?. If this is so do i just need a +/- feed.
If i need to get the correct one and loom why does the loom go all the way to the back of car just to pick up +/-. There is next to no load so i should be able to pick up off another power supply without overloading any other circuit?

2. Same with sun visors with light what years are the same, if its just down to socket can wire to + & -