The constitutional proscription against warrantless searches and seizures admits of certain exceptions. Aside from a search incident to a lawful arrest, a warrantless search had been upheld in cases of moving vehicles, and the seizure of evidence in plain view. With regard to the search of moving vehicles, this had been justified on the ground that the mobility of motor vehicles makes it possible for the vehicle to be searched to move out of the locality or jurisdiction in which the warrant must be sought. This is in no way, however gives the police officers unlimited discretion to conduct warrantless searches of automobiles in the absence of probable cause. When a vehicle is stopped and subjected to an extensive search, such a warrantless search has been held to be valid as long as the officers conducting the search have reasonable or probable cause to believe before search that they will find the instrumentality or evidence pertaining to a crime, in the vehicle to be searched (People v. Bagista, 214 SCRA 63 [1992]) [G.R. No. 120365. December 17, 1996]