Until I read your post, from the phone conversation with that girl on MySpace, I was under the impression LP was talking about the 'air' and the 'dna' both from the car. BUT, I didn't know about the dumpster until last night. I still didn't put it together until your post.
You may be right. He may be talking about the 'air' from the car and then the 'dumpster' dna. Either way, the 'air' of a dead body and Caylee's dna either in the trunk (which would most likely be hair from a dead Caylee) OR Caylee's dna in the dumpster, would be dam#ing evidence.
Whichever one it is, LP was using that, TWO SOURCES of evidence of Caylee being deceased, that he made his decision to pull out. That is what I understood from his phone conversation with that girl.
It seems he revealed different type of 'evidence' but yet the SAME sort of 'evidence,' in both his conversation with that girl on MySpace and NG last night.
JMHO
fran