This. First is the patent search. I would say do one yourself, before hiring a patent attorney. At some point, though, unless you want to make "getting a patent" your new job, you will need to turn it over to a patent atty. Keep a list of all the art you looked at, because it will save him some time and his time is YOUR money. So to be patentable, you have to have an idea that can be distinguished from the prior art, which isn't obvious to a Person of Ordinary Skill in the Art (POSITA). Something that is obvious is jargon -- it means something that is just a combination of a couple of things that already existed and were obvious to put together. Something like (bad example off the top of my head) putting a known airplane de-icing device on a car to solve a car icing problem. That would likely be considered obvious. Making a new de-icing system that is similar in concept to the plane version but has been changed to address specific needs of cars is something that is more patentable. Note that at the end of the day, what your patent will actually cover will be that new, novel idea MINUS what is already in the art. You will only be able to protect that one little part.