Getting auto insurance quotes does not harm your credit score.
When you get an auto insurance quote from auto insurance company they do pull your credit to use it in the deciding factor of your insurance premiums but when the auto insurance company checks your credit they put a soft inquiry on the credit report which does not affect your credit score like a hard inquiry would when a loan company or credit card company checks your credit.
So you can shop for auto insurance as much as you want and get as many auto insurance quotes as you want too without harming your credit score.