That sentence alone tells me a lot. I get very intimate with my projects and I can’t bear to even think about losing them, let alone selling them. If you get tired of a project or you feel like you need to do something else, it’s the project that consumes you, not the car. I think you should start looking at this from a slightly different perspective. Instead of thinking that a car would be cool if you did such-and-such to it, think about if you could take such-and-such and also turn a profit. Don’t lose out on the situation, use your hobby as a source of income. Even if you just break even you’re actually profiting(mentally) since your hobby has been funded 100% by the sales. No more spending, it’s self-sufficient.