how do you do it
To understand how it is that some guys make substantial progress I don't think it's beneficial to know what each person does for a living. That's not the key.
In addition to my own projects I've helped other guys finish theirs. The biggest obstacle standing in their way was themselves. A lot of guys have projects that may never get done because they haven't found the resolve to finish them. They always have an excuse.
Not enough money.
Not enough time.
Can't find parts.
Don't know how to do things.
If you spent cash on anything other than essentials - you had money.
If you slept last night, - you had time.
If you're on this website you have a computer. - Eventually you'll find your parts. - And the information on how to get things done is on sites like this one.
Some people will think that this is a harsh over-simplication of what it takes to get a car finished. But it's true.
Those guys that I had helped had been sitting on their unfinished projects for years. I berated them by telling them they "might as well give up." "You're never going to get it done because you aren't even trying to."
I told them that all it would take is 5 minutes a day. If they would dedicate themselves to working on it for 5 minutes each day, they'd get it done. If they did nothing more than remove a couple of trim pieces or strip off 6 square inches of paint each day, - they'd get there.
When they finally took my advice they saw progress getting done. Naturally, the 5 minutes eventually became 10 and then 30. Before you knew it they more became enthusiastic about their projects and could see the light at the end of the tunnel.
If they couldn't afford certain parts, they'd either have to consider cheaper alternatives or shift focus onto another aspect of their project until they saved up enough.
They didn't have to ignore their families or other obligations.
I procrastinated far too long on my own work before I realized that I was my own worst obstacle.
As the saying goes"Every journey begins with a single step."