Paying for auto insurance monthly is a good idea if you don't have enough cash to pay up front for 6 months to a year.
However if you can pay auto insurance yearly then you usually get a little discount and savings.
I used to pay my auto insurance monthly when that was all I could afford but now I pay the auto insurance yearly in one lump sum of money.
That way I save about 10 percent on my auto insurance and I don't have to worry about not having insurance.
What I do is set aside the monthly payment I would pay to the auto insurance company and then by the time the auto insurance comes up for renewal again I have the money to pay the auto insurance.
It doesn't matter though whether you pay auto insurance monthly, every 6 months or yearly as auto insurance payments do not affect your credit score but it's a good idea to pay auto insurance yearly or every 6 months if possible.