How much time needs a 1.5 kW solar panel to charge a car electric battery?
You're about right

I've checked your numbers and it looks like you have done the calculation correctly.  150W per square meter is pretty good, most panels will be a bit worse than that, even pointed at the noon sun. I expect an average of 150W for 8h a day is a bit optimistic too. Here in the UK the average is about 10% of the rated output, so it would take about 20 days, not 7. With sun tracking panels and a sunnier climate, you'd do better, but 7 days would be impressive.

You haven't considered efficiency losses either. Some energy will be lost in transmission from the panels to the car (either becasue of the huge current flowing, or in the converters mentioned below) and in charging the batteries.  Probably only 10-15%, so not worth worrying about if you're just getting a general estimate.

You might also choose not to charge the batteries at 12V/125A. That would require some very thick, heavy cables - probably 8-10mm diameter copper.  Instead it might be better to connect the solar panels to a converter and step up to 100-200V, ac or dc, and convert back at the car.  Since the car has a built-in converter for 120Vac input, it would make sense to use that.