I once worked as a producer in the BBC crime unit. I directed many reconstructions and spent my second pregnancy producing new investigations for Crimewatch. Detectives would call me daily, detailing their cases, and some stories stay with me still, such as the ones about a girl being snatched from her bath, or her bike, or her garden and then held in the passenger seat, or stuffed in the boot. There was always a vehicle, and the first few hours were crucial to the outcome. Afterwards, they would be dumped naked in an alley, or at a petrol station with a £10 note to "get a cab back to Mummy". They would be found within an hour or two. Sometimes.
It was a welcome spring break, a chance to relax at a child-friendly resort in Portugal. Soon Bridget O'Donnell and her partner were making friends with another holidaying family while their three-year-old daughters played together. But then Madeleine McCann went missing and everyone was sucked...
www.theguardian.com
MM crossed the carpark every day of her stay. The dogs did not go any further than the entrance where both teams lost the scent they had been following. The implication being they were not following MM's daily route.
My opinion. It is possible the trail the dogs followed led to a car parked in the carpark at the spot where the dogs lost the scent.