The 360 didn’t change that much over its 11 year production run, but most of the changes happened in the first three or four years, so a first year car is pretty interesting.
This car is a ‘58, the first year Subarus were made. They made less than 1000 cars that year, so these are super rare. This car does have a few later parts on it, like the front bumper, but appears to mostly be original.
The single windshield wiper, the low mounted headlights, were features only found on cars in the first three years (well the Standard trim kept the small headlights into 1961). ‘58 was the only year of 360 without a cowl vent. One big failure of the original design, which was fixed quickly in 1959, was the inadequate ventilation of the car. The ‘58 had a ventilator mounted in the foot well which took in air from the “trunk” area up front - this is why Subaru 360s have the goofy little grill on the front. The door windows were revised in 1959 to allow more air in too.
I can’t figure out, because my Japanese is so bad, is if this car has the proper 1958 windows or not. I believe the ‘58 cars had sliding windows, but no hinged quarter light, and were revised in ‘59 to introduce the hinged window for better air flow into the cabin. But this car appears to have fixed windows, and a quarter light - so maybe that is correct, and the sliding windows were introduced for ‘59. In any event I know the windows windows and vents were revised for ‘59 and the’58 is the only.