I can't speak for what Lem does, but for me, I like the inking process done via Illustrator first and then brought in to Photoshop. For me, the reason being is that you can do more with the line work using custom brushes. That's for me, pertaining to mostly experience with character art where you see a lot of thick n thin and end points. It can be done in Photoshop also.. Just easier for me in Illy. I've seen some people do some fantastic inking in Photoshop tho, so it might be like.. Mac versus PC or Illy vrs Corel. LOL. For cars, I can see the use of more consistent line work with a slight taper here and there being done just as easily in Photoshop. Maybe Lem can elaborate on his preferences.