Dirty diapers, did'nt the McCanns, or a family member explain the reason cadaver dogs picked up on the hire car because the McCanns drove around with dirty diapers from the twins in the trunk of their car? a car hired after Maddie vanished !
http://trueprofiler.wordpress.com/2011/11/04/criminal-profiler-pat-brown-discusses-missing-baby-lisa-irwin-on-cnns-outfront/
http://trueprofiler.wordpress.com/2011/11/04/criminal-profiler-pat-brown-discusses-missing-baby-lisa-irwin-on-cnns-outfront/