there is a lazy man's shortcut sort of option for complex designs that don't warrent the time required to properly weld everything, like when the client is more cheap then picky.
If you have vectorizing software like Adobe Streamline (or I guess Flexi has vectorizing capabilities which I've never used) you can print out the file (with "hidden" lines still hidden) ...then if you get a print that looks like you want the final vinyl to look, you can just scan it and vectorize it.
That method results in rougher lines & sloppier corners & curves... but until you get proficient in redraws, it may come in useful for those complex jobs for cheap people.