If you have bad/questionable credit, ALWAYS make sure that you ask the company you're getting a quote from if they base your premium on your credit score. The major ones, such as Allstate (they're the worst!!!!), Progressive and GEICO are among the worst of the worst when it comes to this. Allstate makes it seem as if it's their god given right to treat people with bad credit like they're lowlifes, and then proceed to charge them as much as humanly possible.
Some time ago, apparently some )@#*$* insurance company hired an "impartial"

agency to do a study, which concluded that people with bad credit make for a higher risk of driver (imagine that!!!!!), and the government went along with it, and guess what??? Even if you have a
perfect driving record, if you have bad credit, you're going to be paying
at least double what you would pay than if you had good credit.
I'm not sure what states my insurance company covers, but I saved almost
75% from what GEICO was charging me, for the
exact same coverage.
I'm with Erie insurance, and they're great. I was in an accident 2 months ago (not my fault,) and they've been on the ball in regards to paying my medical bills as soon as they are presented to them from the hospital/doctors/physical therapist, etc.
I currently have full coverage, and I'm only paying roughly $40 a month for coverage which includes a $200 comp, and $1000 collision deductible, along with Rental coverage for both instances.