I do not believe that the McCann parents moved Madeline's body in the back of the Renault scenic hire car 3 week or so later - I think her clothing (pyjamas) was removed from her body and that it was her belongings that were transported in the hatch back / boot of the car. I think it would have been too risky to move the body in the back of that vehicle. I am also as sure as I can be that the pyjama set worn by Madeleine at the time of her disappearence was / is the very same pyjama set that the McCanns paraded in front of the media. It was too big to have belonged to one of the twins. If I am correct in believing this, then it links the McCanns directly to the disposal of Madeline's body...
I think those pink pyjamas belonged to Madeleine, and that prior to them becoming displayed to the press / media, that Kate McCann washed them in the same way she washed Madeline's cuddle cat toy in a bid to get rid of any incriminating evidence that might tie them, and others to the Madeleine disappearance..