I was involved with a hit and run, and I am 18 right now, when does my insurance start decreasing.

right now I am paying $1,100 every 6 months. Also after 2 years if I decide to buy something like a Nissan Altima SE-R with 6 cylinders, will my insurance be higher or lower than the cost mentioned.

Please help, thanks!!!

You can compare how the insurance quotes would change, for example here – autoinsurance.noneto.com