when I first started making youtube video's I planned on mainly focusing on some of my car projects. but realizing I knew nothing about making video's I figured id would just start recording anything I was doing around the shop when I had a few mins to spare and make video's. my big truck repair stuff seems to gain more traction than my car video's but I think a lot of that has to do with that market being far less saturated and the vast majority of the creators that make video's on the large stuff have pretty poor post production quality. where the car topics are a bit more competitive.
the project cars certainly have a much larger audience potential though and there is certainly some crossover between the two.
I certainly think automotive has large growth potential. I am not really interested in doing vlog type videos. someday I would love to get into making some entertainment more kind of roadkill esk type video's but that is beyond my ability at this point let alone budget and time allowance to do that kind of stuff with any kind of upload frequency. so mostly just doing stuff I would be doing even if I never started a YouTube channel.
so for now its still just anything shop related is on the table, cars, semi's, equipment, snow blowers whatever I happen to be working on sometimes you just never know what the algorithm will pickup, focusing on learning how to craft better video's and growing a audience.