Had to try sub-zeuz way of creating doorlines (he does not separate the parts :roll: ). And i can say it rocks.
Any ways. Not sure if the pictures come in order so just read and then look at the pics.
Im using a hood as example
1. Select the edges that will be the line were we are going to extrude.
2. Type in 0.1 in the field next to the chamferbutton and hit enter (a click will do too).
3. Select that small polyline that appeared after we chamfered. Then in the Extrude field type in -0.1 (hit enter). -0.1 is just to match the 0.1 we did in the previous step (you know sharp line etc). Do not deselect anything yet
4. Now type in -0.30 in the extrude field and hit enter. This is just so we can get a deeper "hole".
And thats it. Of course you will probably need some tweaking later
Feel free to C&C and to come with improvements.