Well, if you're really serious and passionate about this, I don't see any harm in your researching invention and licensing. There's a lot of stuff on the net, but I think you have to be careful with the quality of the information. I find you can't beat a good book, and putting 'invention' into the search engine on Amazon will bring up a few. You can also ask at your local library.
As I think you've guessed, the first thing is not to tell another soul until you can do so safely - how to do this is part of the research.
What everyone said above is sensible and the light-heartedness is just because almost everyone in the world has had an idea that will make millions. It's not the idea that does this, but what you do with it. But I see no reason why with some study and the application of your common sense you can't be one of the few who make it, if not with this idea then with another one.
By the way, surely you have a friend who knows something about cars? You don't have to disclose your idea to him or her, or even reveal that you have one. A good, plain discussion on the area around your idea might be very useful at this stage in telling you if your idea is workable. It's likely that people who know about cars have been thinking about something like your idea before, but there's also the possibility they haven't seen what's under their noses.
By the way, you don't need an inventor - you are the inventor. What you need is people to help you prepare your invention for patenting or licensing, if feasible - an engineer, probably, and then patenting or licensing advisors, as well as possibly an attorney - but be aware that this is a minefield that can cost you your dreamt-of millions over the years without any hope of return. You have to test your footing every step of the way, and dont think of borrowing until you know exactly what you're getting into.
Having said all that - good luck with your idea. It's hopes and dreams like yours that keep man climbing towards the stars.
