Did the mechanic sabotage their car?

I was thinking the same. I also thought the mechanic messed with the car. But after watching the film I have come to the conclusion that they just had some really bad luck and the mechanic wasn't one of the killers because we never see him again after he checked their car. If he was in on it we would see him hanging around or trying to kill them.

As for your second question, I don't think the killers would have gone for them if they would have slept in the car and never went back to the motel. Because the killers liked to film everything they did to their victims as we saw on the videotapes they found. They like to torture them for a good while before they kill them. As far as we can tell from a a couple of videotapes they did all their killings in the room with all the hidden cameras.

I thought the mechanic was one of the killers, as I recall him wearing a jumpsuit like the killers are wearing. He just puts on a mask later on.

No bro, it was the raccoon they ran over. The raccoon totally sabotaged the car because it was the kingpin of the snuff film ring.

That dude who got pinned by the car was the mechanics evil twin brother. Total coincidence.

Was that a serious question?

Watching it now and reckon the mechanic's dodge, otherwise there'd be no point in him making an appearance...

the mechanic does sabotage their car

same actor is the mechanic whom gets rammed by Kate's car at the end

If i go crazy will you still call me Superman?

Did you not pay attention? The mechanic was the SAME GUY Amy killed at the end. We see him without a mask after being crushed by the car.

I also missed the mechanic guy getting rammed by the car.
But I was looking for him.

1. He was creepy.
2. He was at the same gas station where he "fixed" the car.
3. The car failed at a much shorter distance than the 20 miles promised by him. And 1 mile was just close enough to tempt them to come back to the motel.

So, I concluded he was in on it. I assumed he was one of the masked men.

He also gave her the sparkler, which I'm pretty sure was supposed to be some kind of signal to the others. They were rather inept, though. I doubt they had noticed it, as the clerk fellow seemed surprised to see them come in.