If you are chopping a car and want to select the entire car, there are only two ways I've seen of doing it, using the magic wand and manually creating a selection. the Manual way usually is very slow and the wand is inaccurate, any suggestions?

E.

 

I use the polygonal tool which is manually doing it. The magic wand isn't accurate so its hard to use it.

 

the polygonal lasso or the pen tool set on points, are going to be much faster than using the magic wand tool no matter how slow you go. just because the magic wand tool is gonna select in shades, and miss a lot of little areas that youre gonna have to use a wand or pen tool to get anyway. and you can get much cleaner selections with a wand/pen tool anyway.

you can also try the quick mask tool (Q). go into quick mask with the q button and then use the paintbrush to make your selection. whatever you paint using black will turn transparent red (the selection) and whatever you paint white will erase from the selection.