Pay attention to every word and logic.

First, what exactly is your charge? Read the actual language of the law and match that against facts. You cannot just assume the actual charge against you. Look at your ticket and compare to actual law: http://codes.ohio.gov/orc/45

Second, the question is whether you committed the violation or not. Your reason to commit violation is not as important.

You plan to say: Your honor, I am a good driver who is always very careful, it is just that my car is in the shop, and I am not very familiar with the rental car.

You just admitted being careless.

Find some other argument. I can't invent it for you.