If it were that easy to make more money, everyone would be doing it. I have been trying to generate extra income for several years now. The only way I ever accomplished that was when I was still parting cars out. I made most of my money doing that while I was out of work. I also made most of my money doing that on big ticket items. I still have some stuff left and have been sitting on it for a long time now. I only sell a few things here and there because I don't have anything left that people are in major search of, or shipping is too expensive on the big items to make it feasible for the buyer.
And another thing, if you are just getting by on what you make now, just because you generate a little more income, doesn't mean you can afford a new(er) car. Financial responsibility is key. Finiancial irresponsbility is why this country is in the situation it is in.