1. Seat-belt retractors. Pull them out: Moisture, rust and mildew hides deep inside.

2. Door speakers. They often won't be operational because of water damage.

3. Spare-tire nooks. Often overlooked by cleaners.

4. New components in an older car.

5. Rust in springs under seats.

6. Mud or grit in alternator crevices, behind wiring harnesses and around the small recesses of starter motors, power steering pumps and relays.

7. Excessive rust and flaking metal on the undercarriage that would not normally be associated with newer cars.

8. Upholstery. Musty or mildewed smell that's hard to entirely remove, even with repeated cleaning.