Help on car

Can somebody please give me a tip on how to consistantly create a nice looking door cut and how to place the door in afterwards while keeping it a seperate mesh from the whole car so that the window joined to the opening door/s will remain matched with the cut in which it closes, while subsurfed.
Please help out.
Thanks.


ummm model your door h/e you want to model it…then use the boolean modifier to cut it into the car…?

Thanks for that.