Final answer:
Aaron sat in the middle car.
Step-by-step explanation:
To determine who sat in the middle car, we can use the given information.
- Maren sat in the last car.
- Aaron sat directly behind Sharon.
- Darren sat in one of the cars in front of Aaron.
- At least one person sat between Karen and Darren.
Since Maren is in the last car and Aaron is directly behind Sharon, the only possible arrangement is: Darren, Karen, Aaron, Sharon, and Maren. Therefore, Aaron sat in the middle car.