n3wdesign

So I've looked and looked but cannot seem to find a clear answer (maybe there is not one) I want to start selling on ebay and I know there are millions of people on there selling things that are 100% copy writed and probably should not be on ebay... my question is... Say you want to sell graphics for a truck or motorcycle.. lets say a ford f150. obviously the ford logo is copywrited.. what about the f150 name/logo? If it is, can you sell your own version of it? LIke if you design a decal with either your own font or whatever that says f150.. is this legal because you're not trying to copy an original logo and its your own, or are you not allowed to sell anything that says f150 regardless of what it looks like? Same question could be asked for a motorcycle..say a Honda cbr1000. I'm sure its not legal to copy the CBR1000 logo from Honda, but what if you design your own version of it with your own font and such, is it still illegal, or is it OK because you're not trying to sell a counterfeit version of something you're trying to reproduce and pass off as OEM? I hope that makes sense.. I just want to make sure I dont waste any time by coming up with items to sell if they are not allowed and its confusing because so many other people do it, not sure where the line gets drawn? Thank you!