I have got really far with my car modelling and I am now at the stage of mirroring mu subd geometry, but it is casuing a few prtoblems. Firslt when i select a piece of my car, for examply my back window, and I go to mirror, it mirrors wrong. I have treied it in all the axis, yet even when it reflects in the right access it is still not a 100% mirror, as it has to be rotated manually etc to get it looking exactly the same position as the other piece? Whats the problem?

Also I have found that when I have mirrored sometimes thge actual subd surface turns into a poly? Please help.