Sorry man, but if I knew, maybe I'd be driving something cool to the LoneStar Roundup (instead of a late model daily driver) for the last 6 years!
To answer the question - YES! All the damn time! That's why I've pared my project collection from five to just one - my '56 Plymouth wagon. My wife's O/T Chrysler, and my '66 Dodge and '37 Terraplane are, for all intents and purposes, "done" cars; so I have my attention turned fully towards the '56 wagon. I have to really stay focused and perhaps pick up ONLY a parts car, but NO more projects until the '56 is at least running and drivable. Too many distractions and too little $$$ put the stop to "collecting" projects. With that said, I did pick up a neat little '78 Yamaha 650XS project...must...stop...!
I only have my GTO at this point. I can technically say my dad's cars are also but my main car is my GTO. There have been a lot of times where I say I want this project or that, but then I think about the guys who have piles upon piles of cars and whatever else, and I don't want to be one of them. Gotta do one thing at a time, I can almost guarantee the GTO won't ever be fully finished; at least not in my opinion.