Couple of suggestions on keeping rodents out of your car.
1. Put a bar of Irish Spring in the car, they don't like it for some reason.
or....
2. Put a few Bounce dryer sheets in the car, same reason above. Plus, either one makes your car smell nice.
or....
3. When you go to get a haircut, take a baggie and put some of the hair in the baggie and put that in your car. Sorta funky, but no scent and it works.
I used to have a problem with mice getting into my garage, they'd chewed the end of the rubber stop on the bottom of the garage door off and were getting in at the corner. I usually buzz my hair off with the shears during the summer and I took the hair and piled it up behind the rail there in the corner, voila!! no more mice!!!
I got that idea from the movie "The Rookie" where they put hair on the baseball field to keep the deer away.