From experience, you will not be flagged as a "businessman" until you repeat process 10 to 12 times a year (by either RDW, tax authorities, etc). We have a gazillion rules in NL but nobody is really upholding many of them (sad but true), I will probably get backfire from this comment but OK.
A car business from a home address is not going to work, since your municipality will not allow it.
Although building a business from the ground up is a viable and noble plan, starting a capital intensive business like a car business with very little capital can prove challenging.
If I were you (but of course this is informal advice) I'd do two things:
- raise more start capital (flipping more expensive cars gives better margins, as the paperwork, transport, etc. for each car remains the same while % margins go up);
- try if you can get it going with one car as a prove of concept. Don't register a company yet, just take the experience of flipping one car. You learn a lot from it and if it works for you, rethink and fine tune the plan.
Although the market as a whole is in a slump at the moment, the car occasion market is thriving, in that light your idea sure sounds viable.
PS As you are not a native Dutch speaker, where are you from, what is your mother tongue and where are you currently located? I have a background in automotive and the best opportunities are probably in the export business, opposed to the import business you are referring to. Just an idea.