[South40]

You have to be precise in your definition of ‘search’. A sniff around the outside of a vehicle that is parked or stopped (for valid legal reasons) in a public area is not a ‘search’ as it has been defined by the courts. Nobody and nothing has entered into your car. They are detecting the evidence that is leaking out, into the public space.

And no one need enter a house yet the USSC ruled that using a dog to sniff around a house is a "search".

The Supreme Court today said police officers cannot use drug-sniffing dogs along the perimeter of a house without first obtaining a search warrant. In a 5-4 ruling handed down Tuesday, the high court said the use of police-trained dogs to investigate a home's surroundings constitutes a "search," as defined by the Fourth Amendment.
source

I believe the same definition of "search" should apply. Obviously the court disagrees but, as I said, it has been wrong many times before.

[SargeK]

The courts have treated houses differently from mobile things like cars

I’m waiting for the landmark decision on mobile homes .... : ^)

[highball]

“And no one need enter a house yet the USSC ruled that using a dog to sniff around a house is a “search”.

They were on private property long before they got to the house.