i agree with you...but for argument's sake, say it isn't fake. what abductor leaves not one but two items of blood evidence in the room...stashes something (shower curtain, hat, whatever) in the acura klunker, then sits in the driver's seat of the toyota? yet careful enough to leave no prints??? it makes no sense.
no, they didn't confirm there was blood in the klunker...but they certainly found something they didn't like:
KARLINSKY: Yes. This is very curious.
I was there right after the disappearance for more than a week, and we watched police just tearing apart that red car, just going through it methodically day after day. Now we know from these documents they did, in fact, find what they describe as a white hat and also a shower curtain inside with a brown or reddish-brown substance on it.
http://transcripts.cnn.com/TRANSCRIPTS/1205/25/ng.01.html
and there was definitely blood in the other car:
"A forensics team
searching for traces of blood, had a positive hit on the driver's seat of a Toyota Corolla parked in the driveway of the Celis home"
http://www.kpho.com/story/18623691/tucson-pd-releases-new-details-on-search-for-isabel
no perp is going to stick around, in his own or his victim's blood, and play leapfrog in the family cars.
and if none of the above is related in any way to isa's disappearance, i do take issue with random blood stains in a little girls' bedroom and the father's car. IMO, JMO, et cetera...