No-no-no!
For a very valuable car it can be worth importing.
For a car that's not valuable, definitely "No"
Now the next Q is, What's valuable and what's not? Where is the cut-off point?
Some say, "If the commission/tax/freight/compliance/registration combination is more than a third of the cost of the car in Japan, the cut-off point has been reached if not breached". The exception would be "rarity" or "exclusivity".
My 2c