**SEVERE SPOILERS ALERT WARNING CAUTION***
In the spirit of LabRats and Hodges i thought i'll do my own little investigation on this eppy beacuse something didn't seem right. And i think i got something.
I don't think Sara is under the car, but in it. It was raining and it was muddy under it, the upper frame of the car (the roof) would have sunk in the mud, leaving sara trying to climb out through the windshield or the side window.
There are several reasons why i think this is so
1. Natalie said she didn't kill her. The only way to put Sara under the car is to drop the car on her. There's no way Natalie put her under the car, unless the tow truck driver was an accomplice. If Natalie did put Sara in there after incapacitating her (absolutely Sara wouldn't go down without a fight) , she could have only put her INSIDE the car.
2. Natalie put the doll UNDER the car in the minuature to mislead Grissom.
Guys, there is no way a slim woman like Sara can survive being trapped under 2500 kg of steel, the car would crush her spine and she'd be either dead or disabled after the incident.
The only way she would end up under the car is if the car was dropped on her, and there is noone who can survive such impact. Not to mention that she wouldn't be able to move her arm in this case.
So this is what i think happened.
Sara was putting her kit in the trunk of her car when Natalie sedated her somehow. Since Natalie doesn't have a drivers licence and Saras car was still there, Natalie must have had an accomplice, because there is no way in hell she'd drag Sara's body through the parking lot.
So her accomplice arrives with a vehicle and they both get in. After that, there are several possibilities.
In general though, several things could have happened
1. Sara is INSIDE the car, not under it
2. Sara is not in the desert but tied up in an apartment somewhere and it's all about misleading Grissom and the one under the car is someone else (could be, since we never actually see that it's Sara who Natalie calls in the parking lot)
3.There is a huge plot hole and Sara is indeed under the car and there is no accomplice.
4. Natalie put a gun to Sara's head and forced her to get in the Mustang parked nearby. ( maybe she got another look alike and NOT the car from the crimescene) and then made her make a sharp turn in the desert and roll over - but see that can't be because in the final shot there is no evidence of a roll over, the car had been dropped straight down .
Also i don't know if you guys noticed but also in the final shot , there is a bucket laying near the car, i'm thinking Bleach maybe?
Also , in Empty Eyes, in the end when Grissom takes Sara away, there is Natalie, the janitor, mopping the floor and glancing at them as they pass by