An example would be if an office approached a car and saw an open container of liquor, or if he saw what appeared to be crack rocks on the dash board he would be able to search the rest of the car.
When it comes to searching a house without permission the officer must obtain a warrant and that can be obtained only if a judge is convinced there is PROBALE cause to believe the warrant will produce evidence of a crime. It cannot be because the officer has heard on the street the homeowner is a drug dealer. It cannot be based on the fact that the homeowner has been caught dealing drugs in the past. It must be because at this exact time in history there is reasonable and probably cause to believe that a crime is being committed. In other words it cannot be based on past or future concerns.
The threshold of probable cause in a vehicle and home search is not...
In a vehicle if plain view is suspected or someone is under arrest for dui or any other violation their vehicle can be searched without a warrant.
If a person is under arrest for any crime that does not give law enforcement the right to search their private residence without first convincing a judge there is probable cause and getting a warrant.
CONCLUSION home is more closely protected and secluded from search and seizure than a vehicle is. A home search without permission must almost always contain a warrant, while vehicle searches require warrants much less frequently. In the case of this scenario officers cannot search the house without a warrant but if they can find legitimate reasons to commit traffic stops on the vehicles leaving the house and they find anything illegal in plain view they have the right to search the cars.
